diff --git a/src/internal/m365/collection/drive/collection.go b/src/internal/m365/collection/drive/collection.go
index 4c6be1ab7..60010bc8a 100644
--- a/src/internal/m365/collection/drive/collection.go
+++ b/src/internal/m365/collection/drive/collection.go
@@ -208,7 +208,7 @@ func (oc *Collection) Items(
 	ctx context.Context,
 	errs *fault.Bus,
 ) <-chan data.Item {
-	go oc.populateItems(ctx, errs)
+	go oc.streamItems(ctx, errs)
 	return oc.data
 }
 
@@ -411,9 +411,9 @@ type driveStats struct {
 	itemsFound int64
 }
 
-// populateItems iterates through items added to the collection
+// streamItems iterates through items added to the collection
 // and uses the collection `itemReader` to read the item
-func (oc *Collection) populateItems(ctx context.Context, errs *fault.Bus) {
+func (oc *Collection) streamItems(ctx context.Context, errs *fault.Bus) {
 	var (
 		stats driveStats
 		wg    sync.WaitGroup
@@ -453,7 +453,7 @@ func (oc *Collection) populateItems(ctx context.Context, errs *fault.Bus) {
 			defer func() { <-semaphoreCh }()
 
 			// Read the item
-			oc.populateDriveItem(
+			oc.streamDriveItem(
 				ctx,
 				parentPath,
 				item,
@@ -470,7 +470,7 @@ func (oc *Collection) populateItems(ctx context.Context, errs *fault.Bus) {
 	oc.reportAsCompleted(ctx, int(stats.itemsFound), int(stats.itemsRead), stats.byteCount)
 }
 
-func (oc *Collection) populateDriveItem(
+func (oc *Collection) streamDriveItem(
 	ctx context.Context,
 	parentPath *path.Builder,
 	item models.DriveItemable,
diff --git a/src/internal/m365/collection/drive/collection_test.go b/src/internal/m365/collection/drive/collection_test.go
index 2ec7ea77d..ad2c9cc93 100644
--- a/src/internal/m365/collection/drive/collection_test.go
+++ b/src/internal/m365/collection/drive/collection_test.go
@@ -38,16 +38,16 @@ import (
 // tests
 // ---------------------------------------------------------------------------
 
-type CollectionUnitTestSuite struct {
+type CollectionUnitSuite struct {
 	tester.Suite
 }
 
-func TestCollectionUnitTestSuite(t *testing.T) {
-	suite.Run(t, &CollectionUnitTestSuite{Suite: tester.NewUnitSuite(t)})
+func TestCollectionUnitSuite(t *testing.T) {
+	suite.Run(t, &CollectionUnitSuite{Suite: tester.NewUnitSuite(t)})
 }
 
 // Returns a status update function that signals the specified WaitGroup when it is done
-func (suite *CollectionUnitTestSuite) testStatusUpdater(
+func (suite *CollectionUnitSuite) testStatusUpdater(
 	wg *sync.WaitGroup,
 	statusToUpdate *support.ControllerOperationStatus,
 ) support.StatusUpdater {
@@ -59,7 +59,7 @@ func (suite *CollectionUnitTestSuite) testStatusUpdater(
 	}
 }
 
-func (suite *CollectionUnitTestSuite) TestCollection() {
+func (suite *CollectionUnitSuite) TestCollection() {
 	var (
 		now = time.Now()
 
@@ -281,7 +281,7 @@ func (suite *CollectionUnitTestSuite) TestCollection() {
 	}
 }
 
-func (suite *CollectionUnitTestSuite) TestCollectionReadError() {
+func (suite *CollectionUnitSuite) TestCollectionReadError() {
 	var (
 		t                = suite.T()
 		stubItemID       = "fakeItemID"
@@ -349,7 +349,7 @@ func (suite *CollectionUnitTestSuite) TestCollectionReadError() {
 	require.Equal(t, 1, collStatus.Metrics.Successes, "TODO: should be 0, but allowing 1 to reduce async management")
 }
 
-func (suite *CollectionUnitTestSuite) TestCollectionReadUnauthorizedErrorRetry() {
+func (suite *CollectionUnitSuite) TestCollectionReadUnauthorizedErrorRetry() {
 	var (
 		t                = suite.T()
 		stubItemID       = "fakeItemID"
@@ -417,7 +417,7 @@ func (suite *CollectionUnitTestSuite) TestCollectionReadUnauthorizedErrorRetry()
 }
 
 // Ensure metadata file always uses latest time for mod time
-func (suite *CollectionUnitTestSuite) TestCollectionPermissionBackupLatestModTime() {
+func (suite *CollectionUnitSuite) TestCollectionPermissionBackupLatestModTime() {
 	var (
 		t            = suite.T()
 		stubItemID   = "fakeItemID"
@@ -779,7 +779,7 @@ func (suite *GetDriveItemUnitTestSuite) TestDownloadContent() {
 	}
 }
 
-func (suite *CollectionUnitTestSuite) TestItemExtensions() {
+func (suite *CollectionUnitSuite) TestItemExtensions() {
 	type verifyExtensionOutput func(
 		t *testing.T,
 		info details.ItemInfo,
diff --git a/src/internal/m365/collection/exchange/collection_test.go b/src/internal/m365/collection/exchange/collection_test.go
index 03becd45f..ed15bfe3e 100644
--- a/src/internal/m365/collection/exchange/collection_test.go
+++ b/src/internal/m365/collection/exchange/collection_test.go
@@ -2,59 +2,33 @@ package exchange
 
 import (
 	"bytes"
-	"context"
 	"testing"
+	"time"
 
 	"github.com/alcionai/clues"
-	"github.com/microsoft/kiota-abstractions-go/serialization"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 
 	"github.com/alcionai/corso/src/internal/data"
+	"github.com/alcionai/corso/src/internal/m365/collection/exchange/mock"
 	"github.com/alcionai/corso/src/internal/m365/graph"
+	"github.com/alcionai/corso/src/internal/m365/support"
 	"github.com/alcionai/corso/src/internal/tester"
-	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
-type mockItemer struct {
-	getCount       int
-	serializeCount int
-	getErr         error
-	serializeErr   error
-}
-
-func (mi *mockItemer) GetItem(
-	context.Context,
-	string, string,
-	bool,
-	*fault.Bus,
-) (serialization.Parsable, *details.ExchangeInfo, error) {
-	mi.getCount++
-	return nil, nil, mi.getErr
-}
-
-func (mi *mockItemer) Serialize(
-	context.Context,
-	serialization.Parsable,
-	string, string,
-) ([]byte, error) {
-	mi.serializeCount++
-	return nil, mi.serializeErr
-}
-
-type CollectionSuite struct {
+type CollectionUnitSuite struct {
 	tester.Suite
 }
 
-func TestCollectionSuite(t *testing.T) {
-	suite.Run(t, &CollectionSuite{Suite: tester.NewUnitSuite(t)})
+func TestCollectionUnitSuite(t *testing.T) {
+	suite.Run(t, &CollectionUnitSuite{Suite: tester.NewUnitSuite(t)})
 }
 
-func (suite *CollectionSuite) TestReader_Valid() {
+func (suite *CollectionUnitSuite) TestReader_Valid() {
 	m := []byte("test message")
 	description := "aFile"
 	ed := &Item{id: description, message: m}
@@ -66,7 +40,7 @@ func (suite *CollectionSuite) TestReader_Valid() {
 	assert.Equal(suite.T(), description, ed.ID())
 }
 
-func (suite *CollectionSuite) TestReader_Empty() {
+func (suite *CollectionUnitSuite) TestReader_Empty() {
 	var (
 		empty    []byte
 		expected int64
@@ -81,7 +55,7 @@ func (suite *CollectionSuite) TestReader_Empty() {
 	assert.NoError(t, err, clues.ToCore(err))
 }
 
-func (suite *CollectionSuite) TestCollection_NewCollection() {
+func (suite *CollectionUnitSuite) TestCollection_NewCollection() {
 	t := suite.T()
 	tenant := "a-tenant"
 	user := "a-user"
@@ -105,7 +79,7 @@ func (suite *CollectionSuite) TestCollection_NewCollection() {
 	assert.Equal(t, fullPath, edc.FullPath())
 }
 
-func (suite *CollectionSuite) TestNewCollection_state() {
+func (suite *CollectionUnitSuite) TestNewCollection_state() {
 	fooP, err := path.Build("t", "u", path.ExchangeService, path.EmailCategory, false, "foo")
 	require.NoError(suite.T(), err, clues.ToCore(err))
 	barP, err := path.Build("t", "u", path.ExchangeService, path.EmailCategory, false, "bar")
@@ -154,7 +128,8 @@ func (suite *CollectionSuite) TestNewCollection_state() {
 				"u",
 				test.curr, test.prev, test.loc,
 				0,
-				&mockItemer{}, nil,
+				mock.DefaultItemGetSerialize(),
+				nil,
 				control.DefaultOptions(),
 				false)
 			assert.Equal(t, test.expect, c.State(), "collection state")
@@ -165,16 +140,16 @@ func (suite *CollectionSuite) TestNewCollection_state() {
 	}
 }
 
-func (suite *CollectionSuite) TestGetItemWithRetries() {
+func (suite *CollectionUnitSuite) TestGetItemWithRetries() {
 	table := []struct {
 		name           string
-		items          *mockItemer
+		items          *mock.ItemGetSerialize
 		expectErr      func(*testing.T, error)
 		expectGetCalls int
 	}{
 		{
 			name:  "happy",
-			items: &mockItemer{},
+			items: mock.DefaultItemGetSerialize(),
 			expectErr: func(t *testing.T, err error) {
 				assert.NoError(t, err, clues.ToCore(err))
 			},
@@ -182,7 +157,7 @@ func (suite *CollectionSuite) TestGetItemWithRetries() {
 		},
 		{
 			name:  "an error",
-			items: &mockItemer{getErr: assert.AnError},
+			items: &mock.ItemGetSerialize{GetErr: assert.AnError},
 			expectErr: func(t *testing.T, err error) {
 				assert.Error(t, err, clues.ToCore(err))
 			},
@@ -190,8 +165,8 @@ func (suite *CollectionSuite) TestGetItemWithRetries() {
 		},
 		{
 			name: "deleted in flight",
-			items: &mockItemer{
-				getErr: graph.ErrDeletedInFlight,
+			items: &mock.ItemGetSerialize{
+				GetErr: graph.ErrDeletedInFlight,
 			},
 			expectErr: func(t *testing.T, err error) {
 				assert.True(t, graph.IsErrDeletedInFlight(err), "is ErrDeletedInFlight")
@@ -212,3 +187,107 @@ func (suite *CollectionSuite) TestGetItemWithRetries() {
 		})
 	}
 }
+
+func (suite *CollectionUnitSuite) TestCollection_streamItems() {
+	var (
+		t             = suite.T()
+		start         = time.Now().Add(-1 * time.Second)
+		statusUpdater = func(*support.ControllerOperationStatus) {}
+	)
+
+	fullPath, err := path.Build("t", "pr", path.ExchangeService, path.EmailCategory, false, "fnords", "smarf")
+	require.NoError(t, err, clues.ToCore(err))
+
+	locPath, err := path.Build("t", "pr", path.ExchangeService, path.EmailCategory, false, "fnords", "smarf")
+	require.NoError(t, err, clues.ToCore(err))
+
+	table := []struct {
+		name    string
+		added   map[string]struct{}
+		removed map[string]struct{}
+	}{
+		{
+			name:    "no items",
+			added:   map[string]struct{}{},
+			removed: map[string]struct{}{},
+		},
+		{
+			name: "only added items",
+			added: map[string]struct{}{
+				"fisher":    {},
+				"flannigan": {},
+				"fitzbog":   {},
+			},
+			removed: map[string]struct{}{},
+		},
+		{
+			name:  "only removed items",
+			added: map[string]struct{}{},
+			removed: map[string]struct{}{
+				"princess": {},
+				"poppy":    {},
+				"petunia":  {},
+			},
+		},
+		{
+			name:  "added and removed items",
+			added: map[string]struct{}{},
+			removed: map[string]struct{}{
+				"general":  {},
+				"goose":    {},
+				"grumbles": {},
+			},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			var (
+				t         = suite.T()
+				errs      = fault.New(true)
+				itemCount int
+			)
+
+			ctx, flush := tester.NewContext(t)
+			defer flush()
+
+			col := &Collection{
+				added:         test.added,
+				removed:       test.removed,
+				ctrl:          control.DefaultOptions(),
+				getter:        &mock.ItemGetSerialize{},
+				stream:        make(chan data.Item),
+				fullPath:      fullPath,
+				locationPath:  locPath.ToBuilder(),
+				statusUpdater: statusUpdater,
+			}
+
+			go col.streamItems(ctx, errs)
+
+			for item := range col.stream {
+				itemCount++
+
+				_, aok := test.added[item.ID()]
+				if aok {
+					assert.False(t, item.Deleted(), "additions should not be marked as deleted")
+				}
+
+				_, rok := test.removed[item.ID()]
+				if rok {
+					assert.True(t, item.Deleted(), "removals should be marked as deleted")
+					dimt, ok := item.(data.ItemModTime)
+					require.True(t, ok, "item implements data.ItemModTime")
+					assert.True(t, dimt.ModTime().After(start), "deleted items should set mod time to now()")
+				}
+
+				assert.True(t, aok || rok, "item must be either added or removed: %q", item.ID())
+			}
+
+			assert.NoError(t, errs.Failure())
+			assert.Equal(
+				t,
+				len(test.added)+len(test.removed),
+				itemCount,
+				"should see all expected items")
+		})
+	}
+}
diff --git a/src/internal/m365/collection/exchange/mock/item.go b/src/internal/m365/collection/exchange/mock/item.go
new file mode 100644
index 000000000..774a7faa5
--- /dev/null
+++ b/src/internal/m365/collection/exchange/mock/item.go
@@ -0,0 +1,40 @@
+package mock
+
+import (
+	"context"
+
+	"github.com/microsoft/kiota-abstractions-go/serialization"
+
+	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/fault"
+)
+
+type ItemGetSerialize struct {
+	GetCount       int
+	GetErr         error
+	SerializeCount int
+	SerializeErr   error
+}
+
+func (m *ItemGetSerialize) GetItem(
+	context.Context,
+	string, string,
+	bool,
+	*fault.Bus,
+) (serialization.Parsable, *details.ExchangeInfo, error) {
+	m.GetCount++
+	return nil, &details.ExchangeInfo{}, m.GetErr
+}
+
+func (m *ItemGetSerialize) Serialize(
+	context.Context,
+	serialization.Parsable,
+	string, string,
+) ([]byte, error) {
+	m.SerializeCount++
+	return nil, m.SerializeErr
+}
+
+func DefaultItemGetSerialize() *ItemGetSerialize {
+	return &ItemGetSerialize{}
+}
diff --git a/src/internal/m365/collection/groups/backup_test.go b/src/internal/m365/collection/groups/backup_test.go
index 60c6b4bf3..64403cd10 100644
--- a/src/internal/m365/collection/groups/backup_test.go
+++ b/src/internal/m365/collection/groups/backup_test.go
@@ -83,7 +83,7 @@ func (bh mockBackupHandler) canonicalPath(
 			false)
 }
 
-func (bh mockBackupHandler) getChannelMessage(
+func (bh mockBackupHandler) GetChannelMessage(
 	_ context.Context,
 	_, _, itemID string,
 ) (models.ChatMessageable, *details.GroupsInfo, error) {
diff --git a/src/internal/m365/collection/groups/channel_handler.go b/src/internal/m365/collection/groups/channel_handler.go
index 1512e2dbf..f56f165c5 100644
--- a/src/internal/m365/collection/groups/channel_handler.go
+++ b/src/internal/m365/collection/groups/channel_handler.go
@@ -66,7 +66,7 @@ func (bh channelsBackupHandler) canonicalPath(
 			false)
 }
 
-func (bh channelsBackupHandler) getChannelMessage(
+func (bh channelsBackupHandler) GetChannelMessage(
 	ctx context.Context,
 	teamID, channelID, itemID string,
 ) (models.ChatMessageable, *details.GroupsInfo, error) {
diff --git a/src/internal/m365/collection/groups/collection.go b/src/internal/m365/collection/groups/collection.go
index 23d0c8512..190c3e688 100644
--- a/src/internal/m365/collection/groups/collection.go
+++ b/src/internal/m365/collection/groups/collection.go
@@ -142,12 +142,9 @@ func (col Collection) DoNotMergeItems() bool {
 
 // Item represents a single item retrieved from exchange
 type Item struct {
-	id string
-	// TODO: We may need this to be a "oneOf" of `message`, `contact`, etc.
-	// going forward. Using []byte for now but I assume we'll have
-	// some structured type in here (serialization to []byte can be done in `Read`)
+	id      string
 	message []byte
-	info    *details.GroupsInfo // temporary change to bring populate function into directory
+	info    *details.GroupsInfo
 	// TODO(ashmrtn): Can probably eventually be sourced from info as there's a
 	// request to provide modtime in ItemInfo structs.
 	modTime time.Time
@@ -220,31 +217,30 @@ func (col *Collection) streamItems(ctx context.Context, errs *fault.Bus) {
 	semaphoreCh := make(chan struct{}, col.ctrl.Parallelism.ItemFetch)
 	defer close(semaphoreCh)
 
-	// TODO: add for v1 with incrementals
 	// delete all removed items
-	// for id := range col.removed {
-	// 	semaphoreCh <- struct{}{}
+	for id := range col.removed {
+		semaphoreCh <- struct{}{}
 
-	// 	wg.Add(1)
+		wg.Add(1)
 
-	// 	go func(id string) {
-	// 		defer wg.Done()
-	// 		defer func() { <-semaphoreCh }()
+		go func(id string) {
+			defer wg.Done()
+			defer func() { <-semaphoreCh }()
 
-	// 		col.stream <- &Item{
-	// 			id:      id,
-	// 			modTime: time.Now().UTC(), // removed items have no modTime entry.
-	// 			deleted: true,
-	// 		}
+			col.stream <- &Item{
+				id:      id,
+				modTime: time.Now().UTC(), // removed items have no modTime entry.
+				deleted: true,
+			}
 
-	// 		atomic.AddInt64(&streamedItems, 1)
-	// 		atomic.AddInt64(&totalBytes, 0)
+			atomic.AddInt64(&streamedItems, 1)
+			atomic.AddInt64(&totalBytes, 0)
 
-	// 		if colProgress != nil {
-	// 			colProgress <- struct{}{}
-	// 		}
-	// 	}(id)
-	// }
+			if colProgress != nil {
+				colProgress <- struct{}{}
+			}
+		}(id)
+	}
 
 	// add any new items
 	for id := range col.added {
@@ -265,7 +261,7 @@ func (col *Collection) streamItems(ctx context.Context, errs *fault.Bus) {
 			flds := col.fullPath.Folders()
 			parentFolderID := flds[len(flds)-1]
 
-			item, info, err := col.getter.getChannelMessage(
+			item, info, err := col.getter.GetChannelMessage(
 				ctx,
 				col.protectedResource,
 				parentFolderID,
diff --git a/src/internal/m365/collection/groups/collection_test.go b/src/internal/m365/collection/groups/collection_test.go
index 5879d64c4..de89a0808 100644
--- a/src/internal/m365/collection/groups/collection_test.go
+++ b/src/internal/m365/collection/groups/collection_test.go
@@ -3,6 +3,7 @@ package groups
 import (
 	"bytes"
 	"testing"
+	"time"
 
 	"github.com/alcionai/clues"
 	"github.com/stretchr/testify/assert"
@@ -10,20 +11,23 @@ import (
 	"github.com/stretchr/testify/suite"
 
 	"github.com/alcionai/corso/src/internal/data"
+	"github.com/alcionai/corso/src/internal/m365/collection/groups/mock"
+	"github.com/alcionai/corso/src/internal/m365/support"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
-type CollectionSuite struct {
+type CollectionUnitSuite struct {
 	tester.Suite
 }
 
-func TestCollectionSuite(t *testing.T) {
-	suite.Run(t, &CollectionSuite{Suite: tester.NewUnitSuite(t)})
+func TestCollectionUnitSuite(t *testing.T) {
+	suite.Run(t, &CollectionUnitSuite{Suite: tester.NewUnitSuite(t)})
 }
 
-func (suite *CollectionSuite) TestReader_Valid() {
+func (suite *CollectionUnitSuite) TestReader_Valid() {
 	m := []byte("test message")
 	description := "aFile"
 	ed := &Item{id: description, message: m}
@@ -35,7 +39,7 @@ func (suite *CollectionSuite) TestReader_Valid() {
 	assert.Equal(suite.T(), description, ed.ID())
 }
 
-func (suite *CollectionSuite) TestReader_Empty() {
+func (suite *CollectionUnitSuite) TestReader_Empty() {
 	var (
 		empty    []byte
 		expected int64
@@ -50,7 +54,7 @@ func (suite *CollectionSuite) TestReader_Empty() {
 	assert.NoError(t, err, clues.ToCore(err))
 }
 
-func (suite *CollectionSuite) TestCollection_NewCollection() {
+func (suite *CollectionUnitSuite) TestCollection_NewCollection() {
 	t := suite.T()
 	tenant := "a-tenant"
 	protectedResource := "a-protectedResource"
@@ -74,7 +78,7 @@ func (suite *CollectionSuite) TestCollection_NewCollection() {
 	assert.Equal(t, fullPath, edc.FullPath())
 }
 
-func (suite *CollectionSuite) TestNewCollection_state() {
+func (suite *CollectionUnitSuite) TestNewCollection_state() {
 	fooP, err := path.Build("t", "u", path.GroupsService, path.ChannelMessagesCategory, false, "foo")
 	require.NoError(suite.T(), err, clues.ToCore(err))
 	barP, err := path.Build("t", "u", path.GroupsService, path.ChannelMessagesCategory, false, "bar")
@@ -135,3 +139,107 @@ func (suite *CollectionSuite) TestNewCollection_state() {
 		})
 	}
 }
+
+func (suite *CollectionUnitSuite) TestCollection_streamItems() {
+	var (
+		t             = suite.T()
+		start         = time.Now().Add(-1 * time.Second)
+		statusUpdater = func(*support.ControllerOperationStatus) {}
+	)
+
+	fullPath, err := path.Build("t", "pr", path.GroupsService, path.ChannelMessagesCategory, false, "fnords", "smarf")
+	require.NoError(t, err, clues.ToCore(err))
+
+	locPath, err := path.Build("t", "pr", path.GroupsService, path.ChannelMessagesCategory, false, "fnords", "smarf")
+	require.NoError(t, err, clues.ToCore(err))
+
+	table := []struct {
+		name    string
+		added   map[string]struct{}
+		removed map[string]struct{}
+	}{
+		{
+			name:    "no items",
+			added:   map[string]struct{}{},
+			removed: map[string]struct{}{},
+		},
+		{
+			name: "only added items",
+			added: map[string]struct{}{
+				"fisher":    {},
+				"flannigan": {},
+				"fitzbog":   {},
+			},
+			removed: map[string]struct{}{},
+		},
+		{
+			name:  "only removed items",
+			added: map[string]struct{}{},
+			removed: map[string]struct{}{
+				"princess": {},
+				"poppy":    {},
+				"petunia":  {},
+			},
+		},
+		{
+			name:  "added and removed items",
+			added: map[string]struct{}{},
+			removed: map[string]struct{}{
+				"general":  {},
+				"goose":    {},
+				"grumbles": {},
+			},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			var (
+				t         = suite.T()
+				errs      = fault.New(true)
+				itemCount int
+			)
+
+			ctx, flush := tester.NewContext(t)
+			defer flush()
+
+			col := &Collection{
+				added:         test.added,
+				removed:       test.removed,
+				ctrl:          control.DefaultOptions(),
+				getter:        mock.GetChannelMessage{},
+				stream:        make(chan data.Item),
+				fullPath:      fullPath,
+				locationPath:  locPath.ToBuilder(),
+				statusUpdater: statusUpdater,
+			}
+
+			go col.streamItems(ctx, errs)
+
+			for item := range col.stream {
+				itemCount++
+
+				_, aok := test.added[item.ID()]
+				if aok {
+					assert.False(t, item.Deleted(), "additions should not be marked as deleted")
+				}
+
+				_, rok := test.removed[item.ID()]
+				if rok {
+					assert.True(t, item.Deleted(), "removals should be marked as deleted")
+					dimt, ok := item.(data.ItemModTime)
+					require.True(t, ok, "item implements data.ItemModTime")
+					assert.True(t, dimt.ModTime().After(start), "deleted items should set mod time to now()")
+				}
+
+				assert.True(t, aok || rok, "item must be either added or removed: %q", item.ID())
+			}
+
+			assert.NoError(t, errs.Failure())
+			assert.Equal(
+				t,
+				len(test.added)+len(test.removed),
+				itemCount,
+				"should see all expected items")
+		})
+	}
+}
diff --git a/src/internal/m365/collection/groups/handlers.go b/src/internal/m365/collection/groups/handlers.go
index f46b3a099..19389a67a 100644
--- a/src/internal/m365/collection/groups/handlers.go
+++ b/src/internal/m365/collection/groups/handlers.go
@@ -45,7 +45,7 @@ type backupHandler interface {
 }
 
 type getChannelMessager interface {
-	getChannelMessage(
+	GetChannelMessage(
 		ctx context.Context,
 		teamID, channelID, itemID string,
 	) (models.ChatMessageable, *details.GroupsInfo, error)
diff --git a/src/internal/m365/collection/groups/mock/getter.go b/src/internal/m365/collection/groups/mock/getter.go
new file mode 100644
index 000000000..cdee35097
--- /dev/null
+++ b/src/internal/m365/collection/groups/mock/getter.go
@@ -0,0 +1,24 @@
+package mock
+
+import (
+	"context"
+
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
+
+	"github.com/alcionai/corso/src/internal/common/ptr"
+	"github.com/alcionai/corso/src/pkg/backup/details"
+)
+
+type GetChannelMessage struct {
+	Err error
+}
+
+func (m GetChannelMessage) GetChannelMessage(
+	ctx context.Context,
+	teamID, channelID, itemID string,
+) (models.ChatMessageable, *details.GroupsInfo, error) {
+	msg := models.NewChatMessage()
+	msg.SetId(ptr.To(itemID))
+
+	return msg, &details.GroupsInfo{}, m.Err
+}
diff --git a/src/internal/operations/test/helper_test.go b/src/internal/operations/test/helper_test.go
index 53742bbda..4ae9fad6f 100644
--- a/src/internal/operations/test/helper_test.go
+++ b/src/internal/operations/test/helper_test.go
@@ -691,11 +691,22 @@ func verifyExtensionData(
 ) {
 	require.NotNil(t, itemInfo.Extension, "nil extension")
 	assert.NotNil(t, itemInfo.Extension.Data[extensions.KNumBytes], "key not found in extension")
-	actualSize := int64(itemInfo.Extension.Data[extensions.KNumBytes].(float64))
 
-	if p == path.SharePointService {
-		assert.Equal(t, itemInfo.SharePoint.Size, actualSize, "incorrect data in extension")
-	} else {
-		assert.Equal(t, itemInfo.OneDrive.Size, actualSize, "incorrect data in extension")
+	var (
+		detailsSize   int64
+		extensionSize = int64(itemInfo.Extension.Data[extensions.KNumBytes].(float64))
+	)
+
+	switch p {
+	case path.SharePointService:
+		detailsSize = itemInfo.SharePoint.Size
+	case path.OneDriveService:
+		detailsSize = itemInfo.OneDrive.Size
+	case path.GroupsService:
+		detailsSize = itemInfo.Groups.Size
+	default:
+		assert.Fail(t, "unrecognized data type")
 	}
+
+	assert.Equal(t, extensionSize, detailsSize, "incorrect size in extension")
 }
diff --git a/src/pkg/services/m365/api/channels.go b/src/pkg/services/m365/api/channels.go
index 8aab2453a..92d799d60 100644
--- a/src/pkg/services/m365/api/channels.go
+++ b/src/pkg/services/m365/api/channels.go
@@ -108,8 +108,6 @@ func (c Channels) GetChannelMessage(
 	ctx context.Context,
 	teamID, channelID, messageID string,
 ) (models.ChatMessageable, *details.GroupsInfo, error) {
-	var size int64
-
 	message, err := c.Stable.
 		Client().
 		Teams().
@@ -123,7 +121,14 @@ func (c Channels) GetChannelMessage(
 		return nil, nil, graph.Stack(ctx, err)
 	}
 
-	info := ChannelMessageInfo(message, size)
+	replies, err := c.GetChannelMessageReplies(ctx, teamID, channelID, messageID)
+	if err != nil {
+		return nil, nil, graph.Wrap(ctx, err, "retrieving message replies")
+	}
+
+	message.SetReplies(replies)
+
+	info := ChannelMessageInfo(message)
 
 	return message, info, nil
 }
@@ -134,12 +139,12 @@ func (c Channels) GetChannelMessage(
 
 func ChannelMessageInfo(
 	msg models.ChatMessageable,
-	size int64,
 ) *details.GroupsInfo {
 	var (
 		lastReply  time.Time
 		modTime    = ptr.OrNow(msg.GetLastModifiedDateTime())
 		msgCreator string
+		content    string
 	)
 
 	for _, r := range msg.GetReplies() {
@@ -169,15 +174,19 @@ func ChannelMessageInfo(
 		msgCreator = ptr.Val(from.GetUser().GetDisplayName())
 	}
 
+	if msg.GetBody() != nil {
+		content = ptr.Val(msg.GetBody().GetContent())
+	}
+
 	return &details.GroupsInfo{
 		ItemType:       details.GroupsChannelMessage,
 		Created:        ptr.Val(msg.GetCreatedDateTime()),
 		LastReplyAt:    lastReply,
 		Modified:       modTime,
 		MessageCreator: msgCreator,
-		MessagePreview: str.Preview(ptr.Val(msg.GetBody().GetContent()), 16),
+		MessagePreview: str.Preview(content, 16),
 		ReplyCount:     len(msg.GetReplies()),
-		Size:           size,
+		Size:           int64(len(content)),
 	}
 }
 
diff --git a/src/pkg/services/m365/api/channels_pager.go b/src/pkg/services/m365/api/channels_pager.go
index ae6b0ee19..bd8932c2d 100644
--- a/src/pkg/services/m365/api/channels_pager.go
+++ b/src/pkg/services/m365/api/channels_pager.go
@@ -214,7 +214,9 @@ func (c Channels) GetChannelMessageReplies(
 	ctx context.Context,
 	teamID, channelID, messageID string,
 ) ([]models.ChatMessageable, error) {
-	return enumerateItems[models.ChatMessageable](ctx, c.NewChannelMessageRepliesPager(teamID, channelID, messageID))
+	return enumerateItems[models.ChatMessageable](
+		ctx,
+		c.NewChannelMessageRepliesPager(teamID, channelID, messageID))
 }
 
 // ---------------------------------------------------------------------------
diff --git a/src/pkg/services/m365/api/channels_test.go b/src/pkg/services/m365/api/channels_test.go
new file mode 100644
index 000000000..bb632ac9c
--- /dev/null
+++ b/src/pkg/services/m365/api/channels_test.go
@@ -0,0 +1,241 @@
+package api_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/internal/common/ptr"
+	"github.com/alcionai/corso/src/internal/tester"
+	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/services/m365/api"
+)
+
+type ChannelsAPIUnitSuite struct {
+	tester.Suite
+}
+
+func TestChannelsAPIUnitSuitee(t *testing.T) {
+	suite.Run(t, &ChannelsAPIUnitSuite{Suite: tester.NewUnitSuite(t)})
+}
+
+func (suite *ChannelsAPIUnitSuite) TestChannelMessageInfo() {
+	var (
+		initial = time.Now().Add(-24 * time.Hour)
+		mid     = time.Now().Add(-1 * time.Hour)
+		curr    = time.Now()
+
+		content = "content"
+		body    = models.NewItemBody()
+	)
+
+	body.SetContent(ptr.To(content))
+
+	tests := []struct {
+		name       string
+		msgAndInfo func() (models.ChatMessageable, *details.GroupsInfo)
+	}{
+		{
+			name: "No body",
+			msgAndInfo: func() (models.ChatMessageable, *details.GroupsInfo) {
+				msg := models.NewChatMessage()
+				msg.SetCreatedDateTime(&initial)
+				msg.SetLastModifiedDateTime(&initial)
+
+				iden := models.NewIdentity()
+				iden.SetDisplayName(ptr.To("user"))
+
+				from := models.NewChatMessageFromIdentitySet()
+				from.SetUser(iden)
+
+				msg.SetFrom(from)
+
+				i := &details.GroupsInfo{
+					ItemType:       details.GroupsChannelMessage,
+					Created:        initial,
+					Modified:       initial,
+					LastReplyAt:    time.Time{},
+					ReplyCount:     0,
+					MessageCreator: "user",
+				}
+
+				return msg, i
+			},
+		},
+		{
+			name: "No Replies - created by user",
+			msgAndInfo: func() (models.ChatMessageable, *details.GroupsInfo) {
+				msg := models.NewChatMessage()
+				msg.SetCreatedDateTime(&initial)
+				msg.SetLastModifiedDateTime(&initial)
+				msg.SetBody(body)
+
+				iden := models.NewIdentity()
+				iden.SetDisplayName(ptr.To("user"))
+
+				from := models.NewChatMessageFromIdentitySet()
+				from.SetUser(iden)
+
+				msg.SetFrom(from)
+
+				i := &details.GroupsInfo{
+					ItemType:       details.GroupsChannelMessage,
+					Created:        initial,
+					Modified:       initial,
+					LastReplyAt:    time.Time{},
+					ReplyCount:     0,
+					MessageCreator: "user",
+					Size:           int64(len(content)),
+					MessagePreview: content,
+				}
+
+				return msg, i
+			},
+		},
+		{
+			name: "No Replies - created by application",
+			msgAndInfo: func() (models.ChatMessageable, *details.GroupsInfo) {
+				msg := models.NewChatMessage()
+				msg.SetCreatedDateTime(&initial)
+				msg.SetLastModifiedDateTime(&initial)
+				msg.SetBody(body)
+
+				iden := models.NewIdentity()
+				iden.SetDisplayName(ptr.To("app"))
+
+				from := models.NewChatMessageFromIdentitySet()
+				from.SetApplication(iden)
+
+				msg.SetFrom(from)
+
+				i := &details.GroupsInfo{
+					ItemType:       details.GroupsChannelMessage,
+					Created:        initial,
+					Modified:       initial,
+					LastReplyAt:    time.Time{},
+					ReplyCount:     0,
+					MessageCreator: "app",
+					Size:           int64(len(content)),
+					MessagePreview: content,
+				}
+
+				return msg, i
+			},
+		},
+		{
+			name: "No Replies - created by device",
+			msgAndInfo: func() (models.ChatMessageable, *details.GroupsInfo) {
+				msg := models.NewChatMessage()
+				msg.SetCreatedDateTime(&initial)
+				msg.SetLastModifiedDateTime(&initial)
+				msg.SetBody(body)
+
+				iden := models.NewIdentity()
+				iden.SetDisplayName(ptr.To("device"))
+
+				from := models.NewChatMessageFromIdentitySet()
+				from.SetDevice(iden)
+
+				msg.SetFrom(from)
+
+				i := &details.GroupsInfo{
+					ItemType:       details.GroupsChannelMessage,
+					Created:        initial,
+					Modified:       initial,
+					LastReplyAt:    time.Time{},
+					ReplyCount:     0,
+					MessageCreator: "device",
+					Size:           int64(len(content)),
+					MessagePreview: content,
+				}
+
+				return msg, i
+			},
+		},
+		{
+			name: "One Reply",
+			msgAndInfo: func() (models.ChatMessageable, *details.GroupsInfo) {
+				msg := models.NewChatMessage()
+				msg.SetCreatedDateTime(&initial)
+				msg.SetLastModifiedDateTime(&initial)
+				msg.SetBody(body)
+
+				iden := models.NewIdentity()
+				iden.SetDisplayName(ptr.To("user"))
+
+				from := models.NewChatMessageFromIdentitySet()
+				from.SetUser(iden)
+
+				msg.SetFrom(from)
+
+				reply := models.NewChatMessage()
+				reply.SetCreatedDateTime(&curr)
+				reply.SetLastModifiedDateTime(&curr)
+
+				msg.SetReplies([]models.ChatMessageable{reply})
+
+				i := &details.GroupsInfo{
+					ItemType:       details.GroupsChannelMessage,
+					Created:        initial,
+					Modified:       curr,
+					LastReplyAt:    curr,
+					ReplyCount:     1,
+					MessageCreator: "user",
+					Size:           int64(len(content)),
+					MessagePreview: content,
+				}
+
+				return msg, i
+			},
+		},
+		{
+			name: "Many Replies",
+			msgAndInfo: func() (models.ChatMessageable, *details.GroupsInfo) {
+				msg := models.NewChatMessage()
+				msg.SetCreatedDateTime(&initial)
+				msg.SetLastModifiedDateTime(&initial)
+				msg.SetBody(body)
+
+				iden := models.NewIdentity()
+				iden.SetDisplayName(ptr.To("user"))
+
+				from := models.NewChatMessageFromIdentitySet()
+				from.SetUser(iden)
+
+				msg.SetFrom(from)
+
+				reply1 := models.NewChatMessage()
+				reply1.SetCreatedDateTime(&mid)
+				reply1.SetLastModifiedDateTime(&mid)
+
+				reply2 := models.NewChatMessage()
+				reply2.SetCreatedDateTime(&curr)
+				reply2.SetLastModifiedDateTime(&curr)
+
+				msg.SetReplies([]models.ChatMessageable{reply1, reply2})
+
+				i := &details.GroupsInfo{
+					ItemType:       details.GroupsChannelMessage,
+					Created:        initial,
+					Modified:       curr,
+					LastReplyAt:    curr,
+					ReplyCount:     2,
+					MessageCreator: "user",
+					Size:           int64(len(content)),
+					MessagePreview: content,
+				}
+
+				return msg, i
+			},
+		},
+	}
+	for _, test := range tests {
+		suite.Run(test.name, func() {
+			chMsg, expected := test.msgAndInfo()
+			assert.Equal(suite.T(), expected, api.ChannelMessageInfo(chMsg))
+		})
+	}
+}
diff --git a/src/pkg/services/m365/api/contacts_test.go b/src/pkg/services/m365/api/contacts_test.go
index 55f059d04..402b0f4e9 100644
--- a/src/pkg/services/m365/api/contacts_test.go
+++ b/src/pkg/services/m365/api/contacts_test.go
@@ -46,9 +46,11 @@ func (suite *ContactsAPIUnitSuite) TestContactInfo() {
 					Created:  initial,
 					Modified: initial,
 				}
+
 				return contact, i
 			},
-		}, {
+		},
+		{
 			name: "Only Name",
 			contactAndRP: func() (models.Contactable, *details.ExchangeInfo) {
 				aPerson := "Whole Person"
@@ -56,12 +58,14 @@ func (suite *ContactsAPIUnitSuite) TestContactInfo() {
 				contact.SetCreatedDateTime(&initial)
 				contact.SetLastModifiedDateTime(&initial)
 				contact.SetDisplayName(&aPerson)
+
 				i := &details.ExchangeInfo{
 					ItemType:    details.ExchangeContact,
 					ContactName: aPerson,
 					Created:     initial,
 					Modified:    initial,
 				}
+
 				return contact, i
 			},
 		},