14 DAY TRIAL // There’s no doubt Microsoft’s Exchange services have a lot to deal with these days, and the company itself warns that high message volumes for a mailbox or tenant means others would be impacted as well, with email delays hitting other customers by using unnecessary resources.
However, few people know that Microsoft actually had a soft limit in Exchange, only allowing a maximum of 3,600 messages per hour in an Exchange mailbox.
The company has never enforced this limitation, but starting with April 2021, this policy comes into effect in order to maintain the performance of Exchange services for everybody.
“These limits control the amount of messages that a user, group, or public folder can accept in a given hour. When a mailbox exceeds the threshold, any further messages to this mailbox will be throttled. The limit resets after an hour, allowing the mailbox to receive messages again. To ensure that all parties are aware, the throttled recipient will receive a notification that they are being throttled in their Inbox, and any senders to these mailboxes will receive a non-delivery report,” Microsoft explains.
New policy coming into effect in April
While 3,600 messages per hour sounds like a lot, Microsoft says it’ll enforce the new limit gradually originally allowing more mailbox activity before eventually reducing it to this threshold.
“Rollout begins in April, starting at a higher throttling threshold to allow customers time to adjust their mail flow strategy. Before rollout begins, administrators will have access to a new report and insight in the Exchange Admin Center for “Mailboxes exceeding receiving limits.” From here, administrators will be able to track mailboxes that are at risk of hitting the threshold, then reach out to mailbox owners to understand or mitigate the situation,” the company says.
The following products will be impacted by the change:
- Microsoft 365 Business Basic
- Microsoft 365 Business Standard Office
- Office 365 Enterprise E1
- Office 365 Enterprise E3
- Office 365 Enterprise E5
- Office 365 Enterprise F3