Microsoft is implementing new restrictions on the number of external recipient emails that can be sent from a Microsoft 365 tenant. These changes may impact your team’s workflows within Groove.
What's Changing with Microsoft 365 Email Sending?
Microsoft is introducing a tenant-wide limit on outbound external email sending. Starting now through May 1, 2025, Microsoft will begin enforcing a cap on the total number of external recipient emails your entire Microsoft 365 organization can send within a rolling 24-hour period.
This cap applies to all external email activity—including what’s sent via Groove. Groove is just one input into your total volume. To fully understand your exposure, you’ll need to work with your IT team.
Details on the Tenant-Wide Limits
Today, Microsoft 365 allows each user to send up to 5,000 emails/day. Groove’s default Flow email throttle is set at 4,500 to leave room for additional activity.
Under the new model, Microsoft will cap total outbound email volume based on how many Exchange Online licenses your org has. As license count increases, the average number of external emails allowed per user decreases.
Microsoft's rationale for this change appears to be that in most organizations, the majority of users send very few external emails, allowing sales and marketing teams to utilize a larger portion of the tenant's overall email quota.
How This Impacts Groove Users
Groove allows users to send up to 4,500 Flow emails per day. If more are scheduled, Groove automatically reschedules the excess to the following day.
With Microsoft’s changes:
- If your total outbound sending volume—including Groove—exceeds your tenant-wide limit, all users in your organization could be temporarily blocked from sending external emails until the 24-hour window resets.
- Groove cannot track your total Microsoft 365 sending volume. That information lives with your IT team.
- If you want visibility into your team’s Groove-specific Flow volume and top senders, please reach out to your CSM.
What You Should Do
Work with your IT admin to understand your organization’s Microsoft 365 usage:
- Estimated tenant-wide limit formula:
500 * (license count^0.7) + 9500
- To view your current external sending volume:
EAC > Reports > Mail Flow > Tenant Outbound External Recipients Rate
Adjust your Groove send limits if needed:
- Manage My Org > Users > Actions > Set Email Throttle Max
Moving Forward with Confidence
We’re actively monitoring Microsoft’s changes and will communicate any necessary updates to Groove settings.
If you have questions or would like to discuss further, reach out to your CSM