452 4.5.3: recipient needs its own transaction
The receiving domain's policy settings mean Gmail cannot take this recipient in the same transaction as the others, so it asks you to retry it separately.
- Gmail
- Provider
- Temporary (4xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 452 4.5.3
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- TemporaryThe sending server keeps the message and tries again later.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
452 4.5.3 Domain policy size per transaction exceeded, please try this recipient in a separate transaction.
What it means
Google Workspace admins can set routing and compliance rules for their domain, and Gmail applies them to every recipient in a transaction. The reply says the domain policy size per transaction has been exceeded: this transaction already carries as much policy as Gmail will handle, so it answers the extra recipient with this temporary reply and asks for it to be tried in a separate transaction. Google links it to its article on messages bounced by policy rules. A standard mail server handles this on its own by retrying the deferred recipient later. Custom sending code that ignores the reply to each recipient can lose them.
Common causes
- A message addressed to many recipients at a Workspace domain whose admin uses routing or compliance rules.
- Sending software that packs many recipients into one transaction.
How to fix it
- 01Let your mail server retry the deferred recipients; standard servers do this automatically.
- 02If you use custom sending code, read the reply to each RCPT TO and retry deferred recipients in a new transaction.
- 03For large sends to one Workspace domain, put fewer recipients in each transaction.
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
Related codes
- 452 4.5.3Too many recipients.Your message lists more recipients than Gmail accepts at once, so the extra recipients are deferred and need to go in a separate transaction.
- 452Insufficient system storage.The receiving server is short of storage or has hit a limit, such as the number of recipients in one message, and asks the sender to try again later.
- 4.5.3Too many recipients.The message lists more recipients than the server accepts in one transaction; the remaining recipients have to be sent in a separate transaction.
4.5.3 at other providers
All 108 Gmail codesEvery code in the wikiPaste your own bounce