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Comcast (Xfinity) · permanent error

552: message too large

The message is larger than Xfinity accepts. Xfinity takes messages of 15 MB or smaller, so reduce the size and send it again.

Comcast
Provider
Permanent (5xx)
Class
Sources checked
By , email deliverability consultant
Author

At a glance

Code
552
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
552 Message size exceeded

What it means

Xfinity accepts messages up to 15 MB. A larger one is refused with this 552. The size that counts is the whole message as transmitted, and attachments grow by about a third when they are encoded for email, so a file well under 15 MB on disk can still push a message over the limit. The rejection is permanent for that message: it has to be made smaller before it can be delivered.

Common causes

  • Attachments push the encoded message past 15 MB.
  • Large images are embedded in the body of the message.

How to fix it

  1. 01Check the size of the message as sent, including encoded attachments.
  2. 02Compress or shrink attachments and images, or split them across several messages.
  3. 03Share large files as a link to a file-sharing service instead of attaching them.

Sources

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

  1. 552Storage allocation exceeded.The receiving server aborted the message because it exceeded a storage limit, usually a full mailbox or a message larger than allowed.StandardPermanent

552 at other providers

  1. 552Recipient mailbox is full.The recipient's GMX mailbox has no room left, either in storage or in the number of emails it may hold, so the message was refused.GMX, WEB.DEPermanent
  2. 552Message too large.The message is larger than the recipient mailbox or the GMX server accepts, so it was refused. Make it smaller and send it again.GMX, WEB.DEPermanent
  3. 552Recipient mailbox is full.The recipient's IONOS mailbox has no free space left, so the message could not be delivered. Only the recipient can free space.IONOSPermanent

All 33 Comcast codesEvery code in the wikiPaste your own bounce

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