When it comes to sending messages through Microsoft 365, you may have some questions that directly affect your email experience:
- Are any sending size limits applied to email messages?
- What recipient limits are applied to email messages?
The limits on messages, mailboxes, recipients, and email clients fall into one of the following categories:
- Message limits
- Recipient and sender limits
- Retention limits
- Distribution group limits
- Transport rule limits
- Moderation limits
Important - Please be aware of the following:
- The limits applied to your domain may differ depending on how long your domain has been enrolled in the service. When a limit is changed in the Microsoft datacenters, it can take some time to apply the change to all existing customers.
- You can't modify most of these limits, but you should be aware of them.
- These limits apply to both internal and external recipients.
1.) Message limits
- These limits are applied to every email message.
2.) Recipient and sender limits
- These limits are applied to messages, senders, and recipients to combat spam and mass-mailing worms or viruses.
- Note: For distribution groups stored in the shared address book, the group is counted as one recipient. For distribution groups stored in the Contacts folder of a mailbox, the members of the group are counted individually.
3.) Retention limits
- These limits control the amount of time that items in specific folders in the Inbox are accessible.
4.) Distribution group limits
- These limits apply to distribution groups.
5.) Transport rule limits
- These limits control organization-wide rules, als known as transport rules.
6.) Moderation limits
- These limits control moderation settings used for message approval applied to distribution groups and transport rules.