Cleanup immutable ID config passing (#5013)

This value was present in the control.Options in the struct and
passed as a parameter. This PR removes the parameter so it's clear
the control.Options one is used

---

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [x] 🧹 Tech Debt/Cleanup

#### Issue(s)

* #5012

#### Test Plan

- [ ] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E

src/internal/m365/collection/exchange/backup.go

@@ -196,7 +196,6 @@ func populateCollections(
 			cl         = counter.Local()
 			itemConfig = api.CallConfig{
 				CanMakeDeltaQueries: !ctrlOpts.ToggleFeatures.DisableDelta,
-				UseImmutableIDs:     ctrlOpts.ToggleFeatures.ExchangeImmutableIDs,
 			}
 			cID         = ptr.Val(c.GetId())
 			dp          = dps[cID]

src/internal/m365/collection/exchange/backup_test.go

@@ -57,7 +57,6 @@ func (ig mockItemGetter) GetItem(
 	context.Context,
 	string,
 	string,
-	bool,
 	*fault.Bus,
 ) (serialization.Parsable, *details.ExchangeInfo, error) {
 	return models.NewMessage(), &details.ExchangeInfo{}, nil

src/internal/m365/collection/exchange/collection.go

@@ -76,7 +76,6 @@ func getItemAndInfo(
 		ctx,
 		userID,
 		id,
-		useImmutableIDs,
 		fault.New(true)) // temporary way to force a failFast error
 	if err != nil {
 		return nil, nil, clues.WrapWC(ctx, err, "fetching item").

src/internal/m365/collection/exchange/collection_test.go

@@ -217,7 +217,7 @@ func (suite *CollectionUnitSuite) TestGetItemWithRetries() {
 			defer flush()
 
 			// itemer is mocked, so only the errors are configured atm.
-			_, _, err := test.items.GetItem(ctx, "userID", "itemID", false, fault.New(true))
+			_, _, err := test.items.GetItem(ctx, "userID", "itemID", fault.New(true))
 			test.expectErr(t, err)
 		})
 	}
@@ -424,11 +424,10 @@ func (mlg *mockLazyItemGetterSerializer) GetItem(
 	ctx context.Context,
 	user string,
 	itemID string,
-	immutableIDs bool,
 	errs *fault.Bus,
 ) (serialization.Parsable, *details.ExchangeInfo, error) {
 	mlg.callIDs = append(mlg.callIDs, itemID)
-	return mlg.ItemGetSerialize.GetItem(ctx, user, itemID, immutableIDs, errs)
+	return mlg.ItemGetSerialize.GetItem(ctx, user, itemID, errs)
 }
 
 func (mlg *mockLazyItemGetterSerializer) check(t *testing.T, expectIDs []string) {

src/internal/m365/collection/exchange/contacts_container_cache.go

@@ -108,8 +108,7 @@ func (cfc *contactContainerCache) Populate(
 	containers, err := cfc.enumer.EnumerateContainers(
 		ctx,
 		cfc.userID,
-		baseID,
+		baseID)
-		false)
 	ctx = clues.Add(ctx, "num_enumerated_containers", len(containers))
 
 	if err != nil {

src/internal/m365/collection/exchange/container_resolver.go

@@ -30,7 +30,6 @@ type containersEnumerator[T any] interface {
 	EnumerateContainers(
 		ctx context.Context,
 		userID, baseDirID string,
-		immutableIDs bool,
 	) ([]T, error)
 }
 

src/internal/m365/collection/exchange/events_container_cache.go

@@ -82,8 +82,7 @@ func (ecc *eventContainerCache) Populate(
 	containers, err := ecc.enumer.EnumerateContainers(
 		ctx,
 		ecc.userID,
-		"",
+		"")
-		false)
 	ctx = clues.Add(ctx, "num_enumerated_containers", len(containers))
 
 	if err != nil {

src/internal/m365/collection/exchange/events_restore.go

@@ -211,7 +211,6 @@ type attachmentGetDeletePoster interface {
 	attachmentPoster
 	GetAttachments(
 		ctx context.Context,
-		immutableIDs bool,
 		userID string,
 		itemID string,
 	) ([]models.Attachmentable, error)
@@ -238,7 +237,7 @@ func updateAttachments(
 ) error {
 	el := errs.Local()
 
-	attachments, err := agdp.GetAttachments(ctx, false, userID, eventID)
+	attachments, err := agdp.GetAttachments(ctx, userID, eventID)
 	if err != nil {
 		return clues.Wrap(err, "getting attachments")
 	}

src/internal/m365/collection/exchange/events_restore_test.go

@@ -75,7 +75,6 @@ func (m *eventRestoreMock) DeleteAttachment(
 
 func (m *eventRestoreMock) GetAttachments(
 	_ context.Context,
-	_ bool,
 	_, _ string,
 ) ([]models.Attachmentable, error) {
 	return []models.Attachmentable{}, nil

src/internal/m365/collection/exchange/handlers.go

@@ -40,7 +40,6 @@ type itemGetterSerializer interface {
 	GetItem(
 		ctx context.Context,
 		user, itemID string,
-		immutableIDs bool,
 		errs *fault.Bus,
 	) (serialization.Parsable, *details.ExchangeInfo, error)
 	Serialize(

src/internal/m365/collection/exchange/mail_container_cache.go

@@ -112,8 +112,7 @@ func (mc *mailContainerCache) Populate(
 	containers, err := mc.enumer.EnumerateContainers(
 		ctx,
 		mc.userID,
-		"",
+		"")
-		false)
 	ctx = clues.Add(ctx, "num_enumerated_containers", len(containers))
 
 	if err != nil {

src/internal/m365/collection/exchange/mock/item.go

@@ -21,7 +21,6 @@ type ItemGetSerialize struct {
 func (m *ItemGetSerialize) GetItem(
 	context.Context,
 	string, string,
-	bool,
 	*fault.Bus,
 ) (serialization.Parsable, *details.ExchangeInfo, error) {
 	m.GetCount++

src/internal/m365/collection/exchange/restore_test.go

@@ -435,7 +435,7 @@ func (suite *RestoreIntgSuite) TestRestoreAndBackupEvent_recurringInstancesWithA
 	evts := ec.GetValue()
 	assert.Len(t, evts, 1, "count of events")
 
-	sp, info, err := suite.ac.Events().GetItem(ctx, userID, ptr.Val(evts[0].GetId()), false, fault.New(true))
+	sp, info, err := suite.ac.Events().GetItem(ctx, userID, ptr.Val(evts[0].GetId()), fault.New(true))
 	require.NoError(t, err, clues.ToCore(err))
 	assert.NotNil(t, info, "event item info")
 

src/internal/operations/test/m365/exchange/exchange_test.go

@@ -387,7 +387,6 @@ func testExchangeContinuousBackups(suite *ExchangeBackupIntgSuite, toggles contr
 			err error
 			aar pagers.AddedAndRemoved
 			cc  = api.CallConfig{
-				UseImmutableIDs:     toggles.ExchangeImmutableIDs,
 				CanMakeDeltaQueries: true,
 			}
 		)

src/pkg/services/m365/api/client.go

@@ -171,7 +171,6 @@ type CallConfig struct {
 	Expand              []string
 	Select              []string
 	CanMakeDeltaQueries bool
-	UseImmutableIDs     bool
 	// LimitResults limits the returned results to the given number. If 0, returns
 	// all results.
 	LimitResults int

src/pkg/services/m365/api/contacts.go

@@ -185,11 +185,10 @@ func (c Contacts) PatchFolder(
 func (c Contacts) GetItem(
 	ctx context.Context,
 	userID, itemID string,
-	immutableIDs bool,
 	_ *fault.Bus, // no attachments to iterate over, so this goes unused
 ) (serialization.Parsable, *details.ExchangeInfo, error) {
 	options := &users.ItemContactsContactItemRequestBuilderGetRequestConfiguration{
-		Headers: newPreferHeaders(preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 	}
 
 	cont, err := c.Stable.

src/pkg/services/m365/api/contacts_pager.go

@@ -27,11 +27,12 @@ type contactsFoldersPageCtrl struct {
 
 func (c Contacts) NewContactFoldersPager(
 	userID, baseContainerID string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.NonDeltaHandler[models.ContactFolderable] {
 	options := &users.ItemContactFoldersItemChildFoldersRequestBuilderGetRequestConfiguration{
-		Headers:         newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		QueryParameters: &users.ItemContactFoldersItemChildFoldersRequestBuilderGetQueryParameters{},
 		// do NOT set Top.  It limits the total items received.
 	}
@@ -70,9 +71,11 @@ func (p *contactsFoldersPageCtrl) ValidModTimes() bool {
 func (c Contacts) EnumerateContainers(
 	ctx context.Context,
 	userID, baseContainerID string,
-	immutableIDs bool,
 ) ([]models.ContactFolderable, error) {
-	containers, err := pagers.BatchEnumerateItems(ctx, c.NewContactFoldersPager(userID, baseContainerID, immutableIDs))
+	containers, err := pagers.BatchEnumerateItems(ctx, c.NewContactFoldersPager(
+		userID,
+		baseContainerID))
+
 	return containers, graph.Stack(ctx, err).OrNil()
 }
 
@@ -90,11 +93,12 @@ type contactsPageCtrl struct {
 
 func (c Contacts) NewContactsPager(
 	userID, containerID string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.NonDeltaHandler[models.Contactable] {
 	options := &users.ItemContactFoldersItemContactsRequestBuilderGetRequestConfiguration{
-		Headers:         newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		QueryParameters: &users.ItemContactFoldersItemContactsRequestBuilderGetQueryParameters{},
 		// do NOT set Top.  It limits the total items received.
 	}
@@ -134,7 +138,7 @@ func (c Contacts) GetItemsInContainerByCollisionKey(
 	userID, containerID string,
 ) (map[string]string, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewContactsPager(userID, containerID, false, contactCollisionKeyProps()...)
+	pager := c.NewContactsPager(userID, containerID, contactCollisionKeyProps()...)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -155,7 +159,7 @@ func (c Contacts) GetItemIDsInContainer(
 	userID, containerID string,
 ) (map[string]struct{}, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewContactsPager(userID, containerID, false, idAnd()...)
+	pager := c.NewContactsPager(userID, containerID, idAnd()...)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -204,13 +208,14 @@ func getContactDeltaBuilder(
 func (c Contacts) NewContactsDeltaPager(
 	ctx context.Context,
 	userID, containerID, prevDeltaLink string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.DeltaHandler[models.Contactable] {
 	options := &users.ItemContactFoldersItemContactsDeltaRequestBuilderGetRequestConfiguration{
 		// do NOT set Top.  It limits the total items received.
 		QueryParameters: &users.ItemContactFoldersItemContactsDeltaRequestBuilderGetQueryParameters{},
-		Headers:         newPreferHeaders(preferPageSize(c.options.DeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(c.options.DeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 	}
 
 	if len(selectProps) > 0 {
@@ -261,12 +266,10 @@ func (c Contacts) GetAddedAndRemovedItemIDs(
 		userID,
 		containerID,
 		prevDeltaLink,
-		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 	pager := c.NewContactsPager(
 		userID,
 		containerID,
-		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 
 	return pagers.GetAddedAndRemovedItemIDs[models.Contactable](

src/pkg/services/m365/api/events.go

@@ -197,14 +197,13 @@ const (
 func (c Events) GetItem(
 	ctx context.Context,
 	userID, itemID string,
-	immutableIDs bool,
 	errs *fault.Bus,
 ) (serialization.Parsable, *details.ExchangeInfo, error) {
 	var (
 		err    error
 		event  models.Eventable
 		config = &users.ItemEventsEventItemRequestBuilderGetRequestConfiguration{
-			Headers: newPreferHeaders(preferImmutableIDs(immutableIDs)),
+			Headers: newPreferHeaders(preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		}
 	)
 
@@ -226,14 +225,14 @@ func (c Events) GetItem(
 		return nil, nil, clues.Wrap(err, "verify cancelled occurrences")
 	}
 
-	err = fixupExceptionOccurrences(ctx, c, event, immutableIDs, userID)
+	err = fixupExceptionOccurrences(ctx, c, event, userID)
 	if err != nil {
 		return nil, nil, clues.Wrap(err, "fixup exception occurrences")
 	}
 
 	var attachments []models.Attachmentable
 	if ptr.Val(event.GetHasAttachments()) || HasAttachments(event.GetBody()) {
-		attachments, err = c.GetAttachments(ctx, immutableIDs, userID, itemID)
+		attachments, err = c.GetAttachments(ctx, userID, itemID)
 		if err != nil {
 			return nil, nil, err
 		}
@@ -250,7 +249,6 @@ func fixupExceptionOccurrences(
 	ctx context.Context,
 	client Events,
 	event models.Eventable,
-	immutableIDs bool,
 	userID string,
 ) error {
 	// Fetch attachments for exceptions
@@ -282,7 +280,7 @@ func fixupExceptionOccurrences(
 
 		var attachments []models.Attachmentable
 		if ptr.Val(event.GetHasAttachments()) || HasAttachments(event.GetBody()) {
-			attachments, err = client.GetAttachments(ctx, immutableIDs, userID, ptr.Val(evt.GetId()))
+			attachments, err = client.GetAttachments(ctx, userID, ptr.Val(evt.GetId()))
 			if err != nil {
 				return clues.Wrap(err, "getting event instance attachments").
 					With("event_instance_id", ptr.Val(evt.GetId()))
@@ -374,14 +372,15 @@ func parseableToMap(att serialization.Parsable) (map[string]any, error) {
 
 func (c Events) GetAttachments(
 	ctx context.Context,
-	immutableIDs bool,
 	userID, itemID string,
 ) ([]models.Attachmentable, error) {
 	config := &users.ItemEventsItemAttachmentsRequestBuilderGetRequestConfiguration{
 		QueryParameters: &users.ItemEventsItemAttachmentsRequestBuilderGetQueryParameters{
 			Expand: []string{"microsoft.graph.itemattachment/item"},
 		},
-		Headers: newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 	}
 
 	attached, err := c.LargeItem.

src/pkg/services/m365/api/events_pager.go

@@ -30,11 +30,12 @@ type eventsCalendarsPageCtrl struct {
 
 func (c Events) NewEventCalendarsPager(
 	userID string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.NonDeltaHandler[models.Calendarable] {
 	options := &users.ItemCalendarsRequestBuilderGetRequestConfiguration{
-		Headers:         newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		QueryParameters: &users.ItemCalendarsRequestBuilderGetQueryParameters{},
 		// do NOT set Top.  It limits the total items received.
 	}
@@ -71,9 +72,8 @@ func (p *eventsCalendarsPageCtrl) ValidModTimes() bool {
 func (c Events) EnumerateContainers(
 	ctx context.Context,
 	userID, _ string, // baseContainerID not needed here
-	immutableIDs bool,
 ) ([]models.Calendarable, error) {
-	containers, err := pagers.BatchEnumerateItems(ctx, c.NewEventCalendarsPager(userID, immutableIDs))
+	containers, err := pagers.BatchEnumerateItems(ctx, c.NewEventCalendarsPager(userID))
 	return containers, graph.Stack(ctx, err).OrNil()
 }
 
@@ -91,11 +91,12 @@ type eventsPageCtrl struct {
 
 func (c Events) NewEventsPager(
 	userID, containerID string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.NonDeltaHandler[models.Eventable] {
 	options := &users.ItemCalendarsItemEventsRequestBuilderGetRequestConfiguration{
-		Headers:         newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		QueryParameters: &users.ItemCalendarsItemEventsRequestBuilderGetQueryParameters{},
 		// do NOT set Top.  It limits the total items received.
 	}
@@ -135,7 +136,7 @@ func (c Events) GetItemsInContainerByCollisionKey(
 	userID, containerID string,
 ) (map[string]string, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewEventsPager(userID, containerID, false, eventCollisionKeyProps()...)
+	pager := c.NewEventsPager(userID, containerID, eventCollisionKeyProps()...)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -156,7 +157,7 @@ func (c Events) GetItemIDsInContainer(
 	userID, containerID string,
 ) (map[string]struct{}, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewEventsPager(userID, containerID, false, idAnd()...)
+	pager := c.NewEventsPager(userID, containerID, idAnd()...)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -198,13 +199,14 @@ func getEventDeltaBuilder(
 func (c Events) NewEventsDeltaPager(
 	ctx context.Context,
 	userID, containerID, prevDeltaLink string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.DeltaHandler[models.Eventable] {
 	options := &users.ItemCalendarsItemEventsDeltaRequestBuilderGetRequestConfiguration{
 		// do NOT set Top.  It limits the total items received.
 		QueryParameters: &users.ItemCalendarsItemEventsDeltaRequestBuilderGetQueryParameters{},
-		Headers:         newPreferHeaders(preferPageSize(c.options.DeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(c.options.DeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 	}
 
 	if len(selectProps) > 0 {
@@ -256,12 +258,10 @@ func (c Events) GetAddedAndRemovedItemIDs(
 		userID,
 		containerID,
 		prevDeltaLink,
-		config.UseImmutableIDs,
 		idAnd()...)
 	pager := c.NewEventsPager(
 		userID,
 		containerID,
-		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 
 	return pagers.GetAddedAndRemovedItemIDs[models.Eventable](

src/pkg/services/m365/api/events_test.go

@@ -304,8 +304,7 @@ func (suite *EventsAPIIntgSuite) TestEvents_canFindNonStandardFolder() {
 	containers, err := ac.EnumerateContainers(
 		ctx,
 		suite.its.user.id,
-		DefaultCalendar,
+		DefaultCalendar)
-		false)
 	require.NoError(t, err, clues.ToCore(err))
 
 	for _, c := range containers {

src/pkg/services/m365/api/interfaces.go

@@ -17,7 +17,6 @@ type GetItemer[INFO any] interface {
 	GetItem(
 		ctx context.Context,
 		user, itemID string,
-		immutableIDs bool,
 		errs *fault.Bus,
 	) (serialization.Parsable, *INFO, error)
 }

src/pkg/services/m365/api/mail.go

@@ -254,7 +254,6 @@ func (c Mail) GetContainerChildren(
 func (c Mail) GetItem(
 	ctx context.Context,
 	userID, mailID string,
-	immutableIDs bool,
 	errs *fault.Bus,
 ) (serialization.Parsable, *details.ExchangeInfo, error) {
 	var (
@@ -262,7 +261,7 @@ func (c Mail) GetItem(
 		size     int64
 		mailBody models.ItemBodyable
 		config   = &users.ItemMessagesMessageItemRequestBuilderGetRequestConfiguration{
-			Headers: newPreferHeaders(preferImmutableIDs(immutableIDs)),
+			Headers: newPreferHeaders(preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		}
 	)
 
@@ -289,7 +288,7 @@ func (c Mail) GetItem(
 		return mail, MailInfo(mail, size), nil
 	}
 
-	attachments, totalSize, err := c.getAttachments(ctx, userID, mailID, immutableIDs)
+	attachments, totalSize, err := c.getAttachments(ctx, userID, mailID)
 	if err != nil {
 		// A failure can be caused by having a lot of attachments.
 		// If that happens, we can progres with a two-step approach of:
@@ -297,7 +296,11 @@ func (c Mail) GetItem(
 		// 2. fetching each attachment individually.
 		logger.CtxErr(ctx, err).Info("falling back to fetching attachments by id")
 
-		attachments, totalSize, err = c.getAttachmentsIterated(ctx, userID, mailID, immutableIDs, errs)
+		attachments, totalSize, err = c.getAttachmentsIterated(
+			ctx,
+			userID,
+			mailID,
+			errs)
 		if err != nil {
 			return nil, nil, clues.Stack(err)
 		}
@@ -314,7 +317,6 @@ func (c Mail) GetItem(
 func (c Mail) getAttachments(
 	ctx context.Context,
 	userID, mailID string,
-	immutableIDs bool,
 ) ([]models.Attachmentable, int64, error) {
 	var (
 		result    = []models.Attachmentable{}
@@ -323,7 +325,9 @@ func (c Mail) getAttachments(
 			QueryParameters: &users.ItemMessagesItemAttachmentsRequestBuilderGetQueryParameters{
 				Expand: []string{"microsoft.graph.itemattachment/item"},
 			},
-			Headers: newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+			Headers: newPreferHeaders(
+				preferPageSize(maxNonDeltaPageSize),
+				preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		}
 	)
 
@@ -354,7 +358,6 @@ func (c Mail) getAttachments(
 func (c Mail) getAttachmentsIterated(
 	ctx context.Context,
 	userID, mailID string,
-	immutableIDs bool,
 	errs *fault.Bus,
 ) ([]models.Attachmentable, int64, error) {
 	var (
@@ -364,7 +367,9 @@ func (c Mail) getAttachmentsIterated(
 			QueryParameters: &users.ItemMessagesItemAttachmentsRequestBuilderGetQueryParameters{
 				Select: idAnd(),
 			},
-			Headers: newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+			Headers: newPreferHeaders(
+				preferPageSize(maxNonDeltaPageSize),
+				preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		}
 	)
 
@@ -397,7 +402,6 @@ func (c Mail) getAttachmentsIterated(
 			userID,
 			mailID,
 			aID,
-			immutableIDs,
 			isItemAttachment,
 			errs)
 		if err != nil {
@@ -416,14 +420,14 @@ func (c Mail) getAttachmentsIterated(
 func (c Mail) getAttachmentByID(
 	ctx context.Context,
 	userID, mailID, attachmentID string,
-	immutableIDs, isItemAttachment bool,
+	isItemAttachment bool,
 	errs *fault.Bus,
 ) (models.Attachmentable, error) {
 	cfg := &users.ItemMessagesItemAttachmentsAttachmentItemRequestBuilderGetRequestConfiguration{
 		QueryParameters: &users.ItemMessagesItemAttachmentsAttachmentItemRequestBuilderGetQueryParameters{
 			Expand: []string{"microsoft.graph.itemattachment/item"},
 		},
-		Headers: newPreferHeaders(preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 	}
 
 	attachment, err := c.Stable.

src/pkg/services/m365/api/mail_pager.go

@@ -28,11 +28,12 @@ type mailFoldersPageCtrl struct {
 
 func (c Mail) NewMailFoldersPager(
 	userID string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.NonDeltaHandler[models.MailFolderable] {
 	options := &users.ItemMailFoldersRequestBuilderGetRequestConfiguration{
-		Headers:         newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		QueryParameters: &users.ItemMailFoldersRequestBuilderGetQueryParameters{},
 		// do NOT set Top.  It limits the total items received.
 	}
@@ -67,9 +68,8 @@ func (p *mailFoldersPageCtrl) ValidModTimes() bool {
 func (c Mail) EnumerateContainers(
 	ctx context.Context,
 	userID, _ string, // baseContainerID not needed here
-	immutableIDs bool,
 ) ([]models.MailFolderable, error) {
-	containers, err := pagers.BatchEnumerateItems(ctx, c.NewMailFoldersPager(userID, immutableIDs))
+	containers, err := pagers.BatchEnumerateItems(ctx, c.NewMailFoldersPager(userID))
 	return containers, graph.Stack(ctx, err).OrNil()
 }
 
@@ -87,11 +87,12 @@ type mailsPageCtrl struct {
 
 func (c Mail) NewMailPager(
 	userID, containerID string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.NonDeltaHandler[models.Messageable] {
 	options := &users.ItemMailFoldersItemMessagesRequestBuilderGetRequestConfiguration{
-		Headers:         newPreferHeaders(preferPageSize(maxNonDeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(maxNonDeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 		QueryParameters: &users.ItemMailFoldersItemMessagesRequestBuilderGetQueryParameters{},
 		// do NOT set Top.  It limits the total items received.
 	}
@@ -131,7 +132,7 @@ func (c Mail) GetItemsInContainerByCollisionKey(
 	userID, containerID string,
 ) (map[string]string, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewMailPager(userID, containerID, false, mailCollisionKeyProps()...)
+	pager := c.NewMailPager(userID, containerID, mailCollisionKeyProps()...)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -152,7 +153,7 @@ func (c Mail) GetItemsInContainer(
 	userID, containerID string,
 ) ([]models.Messageable, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewMailPager(userID, containerID, false)
+	pager := c.NewMailPager(userID, containerID)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -167,7 +168,7 @@ func (c Mail) GetItemIDsInContainer(
 	userID, containerID string,
 ) (map[string]struct{}, error) {
 	ctx = clues.Add(ctx, "container_id", containerID)
-	pager := c.NewMailPager(userID, containerID, false, idAnd()...)
+	pager := c.NewMailPager(userID, containerID, idAnd()...)
 
 	items, err := pagers.BatchEnumerateItems(ctx, pager)
 	if err != nil {
@@ -216,13 +217,14 @@ func getMailDeltaBuilder(
 func (c Mail) NewMailDeltaPager(
 	ctx context.Context,
 	userID, containerID, prevDeltaLink string,
-	immutableIDs bool,
 	selectProps ...string,
 ) pagers.DeltaHandler[models.Messageable] {
 	options := &users.ItemMailFoldersItemMessagesDeltaRequestBuilderGetRequestConfiguration{
 		// do NOT set Top.  It limits the total items received.
 		QueryParameters: &users.ItemMailFoldersItemMessagesDeltaRequestBuilderGetQueryParameters{},
-		Headers:         newPreferHeaders(preferPageSize(c.options.DeltaPageSize), preferImmutableIDs(immutableIDs)),
+		Headers: newPreferHeaders(
+			preferPageSize(c.options.DeltaPageSize),
+			preferImmutableIDs(c.options.ToggleFeatures.ExchangeImmutableIDs)),
 	}
 
 	if len(selectProps) > 0 {
@@ -273,12 +275,10 @@ func (c Mail) GetAddedAndRemovedItemIDs(
 		userID,
 		containerID,
 		prevDeltaLink,
-		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 	pager := c.NewMailPager(
 		userID,
 		containerID,
-		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 
 	return pagers.GetAddedAndRemovedItemIDs[models.Messageable](

src/pkg/services/m365/api/mail_test.go

@@ -375,7 +375,6 @@ func (suite *MailAPIIntgSuite) TestMail_attachmentListDownload() {
 				ctx,
 				"user",
 				mid,
-				false,
 				fault.New(true))
 			test.expect(t, err)
 
@@ -561,7 +560,6 @@ func (suite *MailAPIIntgSuite) TestMail_PostAndGetAttachments() {
 				ctx,
 				userID,
 				ptr.Val(m.GetId()),
-				false,
 				fault.New(true))
 			require.NoError(t, err, clues.ToCore(err))
 
@@ -723,7 +721,6 @@ func sendItemWithBodyAndGetSerialized(
 		ctx,
 		userID,
 		ptr.Val(item.GetId()),
-		false,
 		fault.New(true))
 	require.NoError(t, err, clues.ToCore(err))
 
@@ -755,7 +752,6 @@ func sendSerializedItemAndGetSerialized(
 		ctx,
 		userID,
 		ptr.Val(item.GetId()),
-		false,
 		fault.New(true))
 	require.NoError(t, err, clues.ToCore(err))