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5.3.4 Message too big for system

The message is larger than the receiving system can handle.

5.3.4 Message too big for system

Permanent: retrying will not help

The message is larger than the receiving system can handle.

Usual causes
  • A large attachment, or a message with a very large HTML body.
What to do
  • Make the message smaller. Keep the whole message, with attachments, comfortably under 10 MB. Gmail also cuts off the display of messages over about 102 KB of HTML.

Usually the fault of: sender.

Common questions.

What does 5.3.4 mean?

The message is larger than the receiving system can handle.

Will retrying fix 5.3.4?

No. It is a permanent failure, so retrying the same message will not help, and repeated attempts can hurt your sending reputation. Fix the cause first.

How do I fix 5.3.4?

Make the message smaller. Keep the whole message, with attachments, comfortably under 10 MB. Gmail also cuts off the display of messages over about 102 KB of HTML.

Other codes: 5.1.1 · 5.1.2 · 5.1.3 · 5.1.6 · 5.2.1 · 5.2.2 · 5.2.3 · 5.4.1 · Decode a whole bounce message

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