O365 account keeps getting blocked

I have a user that keeps getting blocked by O365 for sending out 100+ emails within 24 hours

I know I can unblock via Action Centre but is there a way to stop an account from being blocked?

This is the message I got before I unblocked the account:

Reason:OutboundSpamLast24Hours=189;OutboundMailLast24Hours=191;OutboundSpamPercent=989;Last Message MessagetraceId:603c5478-7c98-4746-1751-08d5a8aaedf7
Date:22/04/2018 11:44 PM

Hi Chong,

Thanks for your post. The answer might be no. As Office 365 Exchange Online is not used for Bulk sending emails, this user may be blocked for exceeding the sending limits of Office 365 Exchange Online, 30 messages per minute sending or other sending limits, and these emails sent from him might be verified as spam. These sending limits help to protect the health of our systems and keep our users safe (For reference: Receiving and sending limits). If a user is blocked, you can unblock this user in the Office 365 action center as you know.

But for spam policies and security reason, it’s infeasible to set a user’s account prevent from being blocked by server forever. If it’s inconvenient for you and you really want such related settings, it’s recommended to submit a feedback about it and your comments will be valuable. Thanks for your time and understanding.

Besides, for sending emails to multiple recipients, it’s recommended for you to create a distribution lists (sometimes called distribution group or contact group) to include these recipients. For distribution groups stored in an organization's address book, the group is counted as one recipient.


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Question Info

Last updated January 19, 2021 Views 10,023 Applies to: