To keep systems healthy and accounts safe, Google limits the number of Gmail messages users can send per day, and the number of recipients per message.
If your users exceed an email sending limit, they’ll get an error message, such as:
After reaching one of these limits, users can't send new messages for up to 24 hours. However, they can still access their Google Workspace account, get incoming email, and use their other Google services. After the suspension period, sending limits are reset and users can resume sending mail.
Sending limits can change without notice. Limits per day are applied over a rolling 24-hour period, not a set time of day.
Notes:
*Applies to internal and external recipients
When you use the Gmail for mobile app in Google Sync mode, the same Sending limits apply as when you use Gmail in a web browser.
When you use the Gmail for mobile app in IMAP mode, the SMTP sending limits apply.
If a user exceeds their sending limits, their account might be suspended. To get details about the number of messages a user has sent and received, follow the steps for Gmail in User reports: Apps usage.
You might be able activate a suspended account by following the steps in Restore a suspended Gmail account.
User accounts that send spam might be permanently restricted from sending email. For details, go to Google's Spam and abuse policy.
To help reduce the likelihood that Gmail blocks your messages or marks your messages as spam, follow the guidelines in Prevent mail to Gmail users from being blocked or sent to spam.