Outlook: retiring “Contact Masking” (hide suggested recipients) - March 31, 2026

Updated June 10, 2026: We have updated the content. Thank you for your patience.  What’s changing In Outlook, Exchange Online users who receive their AutoComplete suggested recipients from the Microsoft Search service can hide a suggested recipient while addressing an email. For example, selecting the X next to a name in the To/Cc/Bcc suggestions list. This behavior is commonly referred to as “Contact Masking”. We are retiring this feature for users. This does not impact admin controls for contacts. Accounts added to classic Outlook for Windows via POP/IMAP or who are hosting their mailboxes on Exchange On-Premises still use the AutoComplete list for Outlook and will not be impacted by this change. Users can still remove entries from their autocomplete history (for example, suggestions based on past emails they typed). Contacts are not being added, deleted, or modified as part of this change. Email delivery and addressing continue to work as before. When this will happen Contact masking will reach end of support on March 31, 2026. How this affects your organization Who is affected All Outlook users (Desktop, Web, Mobile) with Exchange Online mailboxes who previously hid suggested recipients Why we’re making this change This feature has been a recurring source of customer confusion and escalations, because contacts can be accidentally hidden for one user but not others. While the impact is felt across Microsoft 365 experiences (not just Outlook). It also isn’t managed as a contact entity setting, which creates transparency and compliance challenges. What will change in user experience Previously hidden (masked) suggested recipients may reappear in: Addressing (To/Cc/Bcc suggestions) People suggestions Search                           No new feature will replace contact masking for users. The retirement resolves inconsistent cross‑app behavior, as masking previously applied beyond Outlook even though it was not a suite‑level contact setting. Is Admin Action Required? No action is required for this retirement. You may choose to: Inform users that any previously hidden suggestions may reappear after March 31, 2026. Update internal training or helpdesk materials if they reference contact masking. Review related admin controls that remain available for managing visibility and segmentation:Address Book Policies (ABPs): Address book policies in Exchange Online | Address Books | Exchange Online | Microsoft Learn Microsoft Purview Information Barriers: Learn about Information Barriers | Microsoft Purview | Microsoft Learn Hide recipients from Global Address List / GAL (HiddenFromAddressListsEnabled): Hide recipients from address lists - Manage address lists in Exchange Online | Address list procedures | Microsoft Learn Learn more about the retiring feature: (RETIRING March 31, 2006) Manage suggested recipients in the To, Cc, and Bcc fields in Outlook | Microsoft Support Compliance considerations No compliance considerations identified. Review as appropriate for your organization guidance to users on user level features.