Exchange RFC 6710, RFC 6758 and RFC 4021 compliance
I need to verify whether Exchange Online supports the following SMTP extension RFCs: RFC 6710 - Simple Mail Transfer Protocol Extension for Message Transfer Priorities (MT-PRIORITY) RFC 6758 - Tunneling Plaintext Authentication Credentials Using TLS (CRAM) RFC 4021 - Registration of Mail and MIME Header Field Names Specifically, I need to know: Are these RFCs implemented and advertised in the Exchange Online SMTP EHLO response? Is there official Microsoft documentation that lists the complete set of supported SMTP extensions for Exchange Online? If these RFCs are not supported, is there a published list of unsupported RFCs or a roadmap for future implementation? Context: I'm integrating third-party mail systems that require RFC 6710 (MT-PRIORITY) support for priority message handling. Currently, Microsoft documentation only references RFCs 3030, 2920, 6698, and 8461 as supported extensions, but there is no comprehensive list of unsupported RFCs. Any clarification or documentation would be greatly appreciated.
Accepted Domain Verification Causes Mail Flow Failure to Google Workspace Recipients (No MX Changes)
Scenario Source: - Google Workspace (production) - All users actively using Gmail Target: - Microsoft 365 tenant - Existing Exchange Online users Actions Performed 1. Added the production domain to Microsoft 365. 2. Added only the TXT record required for domain verification. 3. No MX, SPF, or other mail-routing records were changed. 4. Domain verification completed successfully. Observed Behavior - Users in the Microsoft 365 tenant could no longer send email to recipients hosted in Google Workspace using the same domain. - Google Workspace users continued to receive email from external senders. - MX records remained pointing to Google Workspace. Testing Performed 1. Removed the domain from Microsoft 365. Result: Mail flow to Google Workspace users worked normally. 2. Added the domain and TXT verification again. Result: Mail flow failure immediately reoccurred. 3. Repeated the test multiple times with consistent results. Question Is this expected behavior when a domain becomes an accepted domain in Exchange Online, even if MX records remain pointed to Google Workspace? Has anyone experienced similar recipient-resolution or routing behavior during Google Workspace to Microsoft 365 migration preparation?
Account locked
I am the business owner and the only Global Administrator of my Microsoft 365 business tenant. I am completely locked out of my administrator account because Microsoft Authenticator is not working correctly. When I try to sign in, Microsoft offers only two authentication methods: Approve a request in Microsoft Authenticator. Enter a verification code from Microsoft Authenticator. Neither method works. The Authenticator app displays an 8-digit code, but Microsoft requests a 6-digit code. I have no alternative authentication method available, and I cannot access the Microsoft 365 admin centre to reset my MFA settings. Please escalate this case to the Microsoft Data Protection team for sole Global Administrator account recovery and MFA reset. I can provide the necessary evidence to verify my identity, business ownership and tenant ownership.Why do Apple macOS and Ubuntu clients display Exchange meeting times one hour earlier than scheduled
If a meeting is generated from Apple macOS and Ubuntu clients showing the meeting time as one hour earlier than the actual scheduled time email solution is exchange server 2019, what will be the issue.
Staff Email hacked Restored but not able to receive any emails
Could you please advise on the best way to restore emails for a staff member whose email account was recently compromised? I am the account administrator and am trying to recover any missing messages and verify mail flow. I have already used Message Trace, but I can't locate a test message I sent to the user. Any guidance on the appropriate recovery steps or troubleshooting recommendations would be greatly appreciated. Thanks
Business Standard with Exchange Plan 2 NOW only showing 100GB of email space
FOR THE PAST 3 YEARS, we have 15 users with Microsoft Business Standard with 100GB of email storage space and 11 with Microsoft Business Premium with 100GB of email storage. I have 1 Business Standard with Exchange On-line Plan2, and 1 with Exchange On-line Plan2. Both have always jhad 150GB of usable mailbox storage. Both users for several years, leading up to September 18, 2026 had over 100GB of mail in their mailboxes and had no problems sending or receiving email, ever. THEN ALL OF THE SUDDEN on 9/18/2026, these 2 users with Plan 2 are no longer able to receive any email and it now shows their mailbox is full Even though checking active users details about mail for both of these users shows 150GB storage. In investigating further, in the exchange area of the admin portal, checking mailboxes indeed both of these 2 USERS ONLY SHOW 100GB, which is the exact same as all my other users who are not paying for Exchange PLAN 2. HOW DO I REPORT this to Microsoft?
