Gmail and Google Workspace · permanent error
550 5.7.1: daily relay limit reached for the customer
Your Google Workspace organization has relayed as much mail through smtp-relay.gmail.com today as its daily limit allows.
- Gmail
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 550 5.7.1
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
550 5.7.1 Daily SMTP relay sending limit exceeded for this customer.
What it means
The SMTP relay service has a daily limit for the whole Workspace customer, as well as one for each user. Your organization has reached the customer-wide limit, so further relay mail is refused until it resets. Unlike the peak limit, which defers mail for a short while, this one stops relaying for the rest of the day. Google refers admins to the SMTP relay service setting for the limits, or to their administrator for help.
Common causes
- A large send relayed through Google in one day.
- Applications and devices across the organization that together relay more than expected.
- A compromised device sending spam through the relay.
How to fix it
- 01Find which systems relayed the most mail today, using Email Log Search or relay logs.
- 02Stop or slow any unexpected or abusive senders.
- 03Move bulk mail to a dedicated sending service, so the relay is left for operational mail.
- 04Check Google's SMTP relay documentation for the limits, and wait for the reset.
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
- SMTP relay service error messages (Google Workspace Admin Help)knowledge.workspace.google.com
Related codes
- 450 4.2.1Peak SMTP relay limit exceeded.Your Google Workspace organization is sending through smtp-relay.gmail.com faster than its peak relay limit allows, so Google is deferring relay mail for now.
- 550 5.4.5Daily relay limit reached for a user.A Workspace user has sent more mail through smtp-relay.gmail.com today than the SMTP relay service allows for one user.
- 550Mailbox unavailable.The receiving server permanently refused the message for this recipient: the mailbox does not exist, cannot be reached, or the server rejected the message by policy.
- 5.7.1Delivery not authorised.The receiving server refuses the message because this sender is not allowed to send to this recipient, as a result of filtering by host or by recipient.
5.7.1 at other providers
- 550 5.7.1Not authorized to send to this recipient.You do not have permission to send to this recipient, typically a group restricted to certain senders or a recipient protected by a mail flow rule.
- 550 5.7.1Public folder does not accept external mail.An external sender wrote to a mail-enabled public folder in Microsoft 365, which by default accepts mail only from authenticated senders.
- 550 5.7.1Sending IP blocked by Proofpoint Dynamic Reputation.Proofpoint’s IP reputation system has your sending IP on its block list because it has seen spam or viruses from it, so Proofpoint customers refuse your mail.
- 550 5.7.1SPF check failed.The recipient’s Cisco Secure Email gateway checked SPF, found your server not authorised for the sender domain, and its policy rejects that result.
- 550 5.7.1Rejected under your domain’s DMARC policy.Your message failed DMARC, your domain’s DMARC record asks receivers to reject such mail, and the recipient’s Cisco gateway did so.
- 550 5.7.1DMARC verification failed permanently.The Cisco gateway hit a permanent failure while verifying DMARC for your message, and the recipient’s policy rejects such mail. Cisco does not say what produces that failure.
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