550 5.4.5: daily sending limit reached

What it means

This one concerns mail you send through Google, not a recipient's mailbox. Google limits how much a Gmail or Workspace account can send per day, and this account has gone over. Google links the reply to its page on Gmail sending limits. Further messages fail until the limit resets. Hitting it usually means the account is being used for bulk or automated mail it was not meant for or, if you did not send that much, that someone else is sending from it.

Common causes

• Large mailings sent from a personal Gmail or Workspace user account.
• A script or app sending through the account more than expected.
• A compromised account sending spam.

How to fix it

1. 01Stop sending from the account and wait for the limit to reset.
2. 02Check the Sent folder for messages you did not send; if there are any, change the password and review the account's security.
3. 03Move bulk or automated mail to a dedicated sending service or to the Workspace SMTP relay, which has limits of its own.
4. 04Check Google's Gmail sending limits page for the limits that apply to your account.

Sources

What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.

• Gmail SMTP errors and codes (Google Workspace Admin Help)knowledge.workspace.google.com

Further reading

• The standard meaning of 4.4.5: mail system congested