Office 365, Email, Exchange, Office 365 Exchange Limits

Various limits on Exchange Online

Office 365 Email Limits

**Office 365 Limits**
Maximum number of messages per mailbox folder	1 million
Maximum number of messages per folder in the Recoverable Items folder	3 million
Storage quota for Recoverable Items folder	100GB
Maximum number of subfolders per mailbox	10,000
Maximum folder hierarchy depth	300
Message size limit	100 MB
Subject length limit	255 characters
File attachments per message limit	250
Messages received	3,600 per hour
Recipient rate limit	10,000 recipients per day and up to 1000 an hour for Employee
Recipient rate limit (Resource Accounts and 2FA enabled Users)	1,000 recipients per day and up to 500 an hour
Recipient rate limit (Non-2FA enabled Users)	100 recipients per day and up to 50 an hour
Recipient limit	500 per message
Message rate limit (SMTP client submission only)	30 messages per minute
Maximum number of distribution group members	50,000
Maximum message size for large distribution groups (>5,000 members)	2 MB
Exchange ActiveSync device limit	100
Exchange ActiveSync file attachment limit	25 MB
smtp.office365.com max concurrent connections per mailbox limit	3
Junk Email folder retention period	30 days

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Keywords:

Office 365, Email, Exchange, Office 365 Exchange Limits

Doc ID:

90634

Owned by:

Office 3. in University of Illinois Technology Services

Created:

2019-03-26

Updated:

2024-12-05

Sites:

University of Illinois Technology Services