There are limits for recipients, recipient rates, recipient proxy addresses and message rates when using Microsoft 365 Exchange as an alternative Email server.
Feature |
Office 365 Business Essentials |
Office 365 Business Premium |
Office 365 Education |
Office 365 Enterprise E1 |
Office 365 Enterprise E3 |
Office 365 Enterprise E5 |
Office 365 Enterprise K1 |
Recipient rate limit |
10,000 recipients per day |
10,000 recipients per day |
10,000 recipients per day |
10,000 recipients per day |
10,000 recipients per day |
10,000 recipients per day |
10,000 recipients per day |
Recipient limit |
500 recipients |
500 recipients |
500 recipients |
500 recipients |
500 recipients |
500 recipients |
500 recipients |
Recipient proxy address limit |
400 |
400 |
400 |
400 |
400 |
400 |
400 |
Message rate limit (SMTP client submission only) |
30 messages per minute |
30 messages per minute |
30 messages per minute |
30 messages per minute |
30 messages per minute |
30 messages per minute |
30 messages per minute |
Recipient Rate Limit:
After the recipient rate limit is reached, messages can't be sent from the mailbox until the number of recipients that were sent messages in the past 24 hours drops below the limit.
Recipient Limit:
The user should receive a 550 5.5.3 - NDR (Non-Delivery Report)
Recipient Proxy Address Limit:
It's important to note that exceeding the recipient proxy address limit can cause issues with email delivery and other Exchange Server functions
Message Rate Limit:
When outbound message volumes surpass the message rate limit, any excess in message submission will be throttled and successively carried over to the following minutes.
