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All CollectionsErrors in Trulyinbox
smtp; 451 4.4.4 Mail received as unauthenticated, incoming to a recipient domain configured in a hosted tenant which has no mail-enabled subscriptions. ATTR5 [BMXIND01FT019.eop-IND01.prod.protection.outlook.com 2023-10-06T05
smtp; 451 4.4.4 Mail received as unauthenticated, incoming to a recipient domain configured in a hosted tenant which has no mail-enabled subscriptions. ATTR5 [BMXIND01FT019.eop-IND01.prod.protection.outlook.com 2023-10-06T05
TrulyInbox avatar
Written by TrulyInbox
Updated over 7 months ago

This error will show up if the message is sent to have an inactive mailbox subscription.
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Kindly Check if the address the message is sent to have an active mailbox subscription? The error messages indicate there are no licensed mailboxes in the tenant.
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The Microsoft 365 admin can open a support case if you have active licenses. Reach out to Microsoft Support Team for additional details as the error is coming from your ESPs side not Trulyinbox side.

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