diff --git a/src/internal/m365/discovery/discovery_test.go b/src/internal/m365/discovery/discovery_test.go
index f8648cd84..f4ae315f3 100644
--- a/src/internal/m365/discovery/discovery_test.go
+++ b/src/internal/m365/discovery/discovery_test.go
@@ -214,7 +214,7 @@ func (suite *DiscoveryIntgSuite) TestUserInfo() {
 				ServicesEnabled: map[path.ServiceType]struct{}{},
 				Mailbox:         api.MailboxInfo{},
 			},
-			expectErr: require.NoError,
+			expectErr: require.Error,
 		},
 	}
 	for _, test := range table {
diff --git a/src/internal/m365/graph/errors.go b/src/internal/m365/graph/errors.go
index a6a0c7fe1..5bd5cc2bd 100644
--- a/src/internal/m365/graph/errors.go
+++ b/src/internal/m365/graph/errors.go
@@ -38,11 +38,15 @@ const (
 	nameAlreadyExists       errorCode = "nameAlreadyExists"
 	quotaExceeded           errorCode = "ErrorQuotaExceeded"
 	RequestResourceNotFound errorCode = "Request_ResourceNotFound"
-	resourceNotFound        errorCode = "ResourceNotFound"
-	resyncRequired          errorCode = "ResyncRequired" // alt: resyncRequired
-	syncFolderNotFound      errorCode = "ErrorSyncFolderNotFound"
-	syncStateInvalid        errorCode = "SyncStateInvalid"
-	syncStateNotFound       errorCode = "SyncStateNotFound"
+	// Returned when we try to get the inbox of a user that doesn't exist.
+	resourceNotFound errorCode = "ResourceNotFound"
+	// Some datacenters are returning this when we try to get the inbox of a user
+	// that doesn't exist.
+	invalidUser        errorCode = "ErrorInvalidUser"
+	resyncRequired     errorCode = "ResyncRequired"
+	syncFolderNotFound errorCode = "ErrorSyncFolderNotFound"
+	syncStateInvalid   errorCode = "SyncStateInvalid"
+	syncStateNotFound  errorCode = "SyncStateNotFound"
 	// This error occurs when an attempt is made to create a folder that has
 	// the same name as another folder in the same parent. Such duplicate folder
 	// names are not allowed by graph.
@@ -131,7 +135,22 @@ func IsErrExchangeMailFolderNotFound(err error) bool {
 }
 
 func IsErrUserNotFound(err error) bool {
-	return hasErrorCode(err, RequestResourceNotFound)
+	if hasErrorCode(err, RequestResourceNotFound, invalidUser) {
+		return true
+	}
+
+	if hasErrorCode(err, resourceNotFound) {
+		var odErr odataerrors.ODataErrorable
+		if !errors.As(err, &odErr) {
+			return false
+		}
+
+		mainMsg, _, _ := errData(odErr)
+
+		return strings.Contains(strings.ToLower(mainMsg), "user")
+	}
+
+	return false
 }
 
 func IsErrResourceNotFound(err error) bool {
diff --git a/src/internal/m365/graph/errors_test.go b/src/internal/m365/graph/errors_test.go
index 7a415c8c4..ffc1b85d6 100644
--- a/src/internal/m365/graph/errors_test.go
+++ b/src/internal/m365/graph/errors_test.go
@@ -12,6 +12,7 @@ import (
 	"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/fault"
 )
@@ -231,11 +232,36 @@ func (suite *GraphErrorsUnitSuite) TestIsErrUserNotFound() {
 			err:    odErr("fnords"),
 			expect: assert.False,
 		},
+		{
+			name: "non-matching resource not found",
+			err: func() error {
+				res := odErr(string(resourceNotFound))
+				res.GetError().SetMessage(ptr.To("Calendar not found"))
+
+				return res
+			}(),
+			expect: assert.False,
+		},
 		{
 			name:   "request resource not found oDataErr",
 			err:    odErr(string(RequestResourceNotFound)),
 			expect: assert.True,
 		},
+		{
+			name:   "invalid user oDataErr",
+			err:    odErr(string(invalidUser)),
+			expect: assert.True,
+		},
+		{
+			name: "resource not found oDataErr",
+			err: func() error {
+				res := odErr(string(resourceNotFound))
+				res.GetError().SetMessage(ptr.To("User not found"))
+
+				return res
+			}(),
+			expect: assert.True,
+		},
 	}
 	for _, test := range table {
 		suite.Run(test.name, func() {
diff --git a/src/pkg/services/m365/api/users.go b/src/pkg/services/m365/api/users.go
index 286cc52ff..1f21384be 100644
--- a/src/pkg/services/m365/api/users.go
+++ b/src/pkg/services/m365/api/users.go
@@ -200,12 +200,14 @@ func (c Users) GetInfo(ctx context.Context, userID string) (*UserInfo, error) {
 
 		if graph.IsErrUserNotFound(err) {
 			logger.CtxErr(ctx, err).Error("user not found")
-			return nil, clues.Stack(graph.ErrResourceOwnerNotFound, err)
+			// FIXME(ashmrtn): This shouldn't need clues.Wrap.
+			return nil, clues.Wrap(clues.Stack(graph.ErrResourceOwnerNotFound, err), "")
 		}
 
 		if !graph.IsErrExchangeMailFolderNotFound(err) {
 			logger.CtxErr(ctx, err).Error("getting user's mail folder")
-			return nil, err
+			// FIXME(ashmrtn): This should use clues.Stack.
+			return nil, clues.Wrap(err, "")
 		}
 
 		logger.Ctx(ctx).Info("resource owner does not have a mailbox enabled")
@@ -243,7 +245,8 @@ func (c Users) GetInfo(ctx context.Context, userID string) (*UserInfo, error) {
 	err = c.getFirstInboxMessage(ctx, userID, ptr.Val(inbx.GetId()))
 	if err != nil {
 		if !graph.IsErrQuotaExceeded(err) {
-			return nil, err
+			// FIXME(ashmrtn): This should use clues.Stack.
+			return nil, clues.Wrap(err, "")
 		}
 
 		userInfo.Mailbox.QuotaExceeded = graph.IsErrQuotaExceeded(err)