Microsoft 365 - Email/Calendar Recipient Limits FAQ

This document answers questions related to the maximum email/calendar recipient limits within Microsoft 365.

IMPORTANT: Beginning May 12, 2025 there will be new email sending limits for all Microsoft 365 accounts:

  • 2,000 email recipients per day: All paid faculty and staff accounts
  • 500 email recipients per day: All other types of accounts (students, emeriti, and affiliates)
  • Service accounts are not included within the initial roll-out and are currently set at 10000 recipients per day

Learn more.

   

What happens if I send more than my daily limit?

If you exceed your daily email sending limit you will receive a bounce back message that will contain the following error message:

delivery message

You will be blocked from sending additional messages until the next day. There is no way for the Help Desk or the Microsoft 365 team to unblock your account.

How do I unblock my account?

Once you have exceeded your daily sending limit you will need to wait until the next day to send email. This is a Microsoft limitation and there is no way to unblock your account.

How do I request a higher sending limit?

You can request a higher sending limit by filling out the M365 Email Sending Limits: Exception Request form. It may take up to 5 days for us to process your request so plan ahead.

The form asks you to specify an expiration date for the increased sending limit. If you regularly send to a large number of recipients, it is OK to set a date well into the future. Exceptions for student accounts will expire at the end of the current academic year.

We are not accepting requests for Service Accounts at this time. Service Accounts are not part of the initial roll-out and they still have a default limit of 10,000 recipients per day.

What counts against my sending limit?

  • Email: Each recipient listed in the To:, Cc: or Bcc: fields of emails you send counts towards your sending limit.
  • Calendar Invites: Each recipient of a calendar invite that you create counts towards your email sending limit
  • Send As: Messages you send using the Send As feature count toward your account and not the account the From address is assigned to.
  • Send on Behalf: Messages you send using Send on Behalf of permissions count toward your account and not the account you are sending on behalf of.
  • Message Failures: Even if a message fails to be delivered, it still counts toward your sending limit.

What does NOT count against my sending limit?

  • Forwarded Messages: If you have a forward set on your account the forwarded messages do not count against your sending limit.
  • Inbox Rule Redirects: If you have an inbox rule that redirects mail to another account the forwarded messages do not count against your sending limit.
  • Automatic Replies: If you have an Out of Office message configured, the replies do not count against your sending limit.
  • Campus Relay: Emails sent via the campus relay service do not count against an account’s daily sending limit.
  • 3rd Party Services: Email sent from other services using UW-Madison email addresses do not count. (example: Salesforce, Slate, Constant Contact, Mailchimp, Eloqua).

How do I know what my sending limit is set to?

The default limits are determined by your Microsoft 365 license.

  • Faculty and Staff: 2,000 recipients per day
  • Students: 500 recipients per day
  • Emeritus, Retirees, Honorary Appointments and other Affiliates: 500 recipients per day
  • Service Accounts: 10,0000 recipients per day

If you are not sure what your current sending limit is set to, please contact DoIT Help Desk. They will be able to confirm your sending limit for you.

When will sending limits apply to Service Accounts?

We need to evaluate the impact of the initial roll-out before we set a date for the next phase. We will communicate with campus stakeholders well in advance of any change to service account sending limits.

What happens when creating a calendar meeting which fails to send

If you create a calendar meeting that results in a failed delivery bounce-back notice, the event will not appear on any of the attendee’s calendars, but it will still appear on the organizer’s calendar.


Keywords:
microsoft office365 o365 m365 365 quotas limitations limits recipients max maximum outlook clients relay smtp proofpoint proof point email sending limit 
Doc ID:
147909
Owned by:
O365 S. in Microsoft 365
Created:
2025-01-29
Updated:
2025-04-24
Sites:
DoIT Help Desk, Microsoft 365