452: too many recipients in one message
The message listed more recipients than Xfinity accepts at once. Xfinity allows 100 recipients per message, so a larger list has to be split.
- Comcast
- Provider
- Temporary (4xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 452
- Provider
- Comcast (Xfinity)
- 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 Too many recipients for message
What it means
Xfinity accepts up to 100 recipients for a single message. When a message names more, it answers with this 452, a temporary error, and the recipients over the limit have to be sent in another transaction, which standard mail servers do by retrying them. Senders who address one message to many Xfinity customers at once, for example a group mailing in To, Cc or Bcc, are the ones who run into it. Keeping each message to 100 recipients or fewer avoids it.
Common causes
- One message was addressed to more than 100 recipients.
- A mailing list or group send puts many recipients in one envelope.
How to fix it
- 01Let your server retry the remaining recipients in a further transaction.
- 02Limit each message to 100 recipients or fewer for Xfinity domains.
- 03For large mailings, send one message per recipient or in small batches.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
Related codes
- 452Too many emails in one session.Your server sent more messages in one SMTP session than Xfinity accepts. Xfinity allows 1,000 emails per session, so the rest have to go in a new session.
- 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.
452 at other providers
- 452Too many recipients in one message.Your server named more recipients in one transaction than GMX accepts, currently 20 per message, so the rest were deferred. Split the recipients into several transactions.
- 452More than 100 recipients in one message.Mimecast accepts at most 100 recipients per message transaction and asks your server to send the rest in another batch. Most mail servers do this automatically.
- 452Hourly recipient limit reached.Your server sent more recipients to the company’s Cisco gateway this hour than its rate limit allows. The rest are deferred until the limit resets.
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