Gmail
Gmail 550 5.4.5 — daily sending quota exceeded
550 5.4.5
The Google account that sent the message has exhausted its rolling 24-hour sending allowance — around 2,000 recipients/day for Google Workspace accounts and 500 for free Gmail. This is a per-account limit at the sender, not a judgment about your domain, your recipients, or your authentication. Sending resumes automatically as the rolling window clears.
How to fix it
- 1
Wait it out — the limit is rolling, not midnight-reset
The block lifts gradually within 24 hours of the sends that consumed the quota. There is no support path to lift it early; anything urgent should go from a different authorized account in the meantime.
- 2
Find what consumed the quota
It's often not a human: mail-merge add-ons, Apps Script, a CRM connected via SMTP, or a compromised account blasting spam all draw from the same allowance. Check the account's Sent folder and any connected tools — and if you see mail you didn't send, treat it as a compromise and rotate credentials first.
- 3
Move bulk sending off Gmail accounts
Gmail and Workspace are sized for human correspondence. Newsletters, campaigns, and application email belong on an ESP or transactional provider with your domain authenticated there — see the setup guides for the exact records per platform.
- 4
Use Google Groups for large internal announcements
A message to a Group counts as one recipient against your quota regardless of member count — the right mechanism for company-wide mail inside Workspace.
Meaning current as of 2026-07-25, cross-checked against the provider's own documentation. Providers do occasionally redefine codes — if this doesn't match what you're seeing, the source link is the authoritative reference.