Email API
Calendar API
Contacts API 
Scheduler
Notetaker API
Google email & calendar integration
Outlook email & calendar integration
IMAP integration
Google Meet integration
Zoom integration
Microsoft Teams integration
Docs
SDKs
Tutorials
API status
Changelog
Support
Blog
Events
Guides
Inspiration gallery
Build vs. buy
Customer stories
Security & Compliance
Why Nylas
Newsroom
How to fix Microsoft’s “service abuse mode” error
• 3 min read
This post is part of our “What to do when there’s no email admin” series — practical guides for anyone who suddenly finds themselves responsible for email systems they’ve never touched before.
If you missed earlier posts, start with:
If you’re seeing this error when sending through a Microsoft 365 account:
AADSTS70000: User account is found to be in service abuse mode
…it means Microsoft has restricted the mailbox due to spam complaints, security concerns, or behavior that resembles abuse. This is a provider-level block enforced by Microsoft’s anti-abuse systems. It is not a Nylas integration issue.
When an account enters “service abuse mode,” Microsoft essentially places the mailbox in a restricted state until an admin verifies and resolves the root cause.
Even though the account can’t send mail, the grant may still appear valid in the Nylas Dashboard. Nylas keeps it valid because the issue is recoverable. If Microsoft removes the restriction, the same grant can be used again without forcing a full reconnect.
The grant becomes usable only after Microsoft clears the block.
1. Contact the user’s Microsoft 365 admin.
They are the only ones who can initiate the unblock.
2. The admin must open a case with Microsoft Support.
Only Microsoft can remove the service abuse mode restriction.
3. Once Microsoft lifts the block, the user re-authenticates.
After the restriction is removed, have the user re-at their mailbox. The existing Nylas grant will start working again.
Microsoft flags accounts when they see patterns like:
Even minor spikes can trigger protective blocks depending on the tenant’s configuration.
These small steps dramatically reduce the risk of service abuse mode.
The workflow is straightforward once you know what’s happening:
Account is restricted by Microsoft
Admin contacts Microsoft Support
Block is lifted
User re-authenticates
If issues persist after recovery, check sender reputation, content quality, or refer back to earlier posts in this series for deeper diagnostics.
This post is part of our “What to do when there’s no email admin” series.
If you haven’t yet, read earlier entries:
This post is part of our “What to do when there’s no email admin” series…
This post is part of our “What to do when there’s no email admin” series…
This post is part of our “What to do when there’s no email admin” series…
Sr. Manager, Technical Support Engineering