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551 User not local, please try a forwarding address

The mailbox is not on this server. The reply may name the address to use instead.

551 User not local, please try a forwarding address

Permanent: retrying will not help

The mailbox is not on this server. The reply may name the address to use instead.

Usual causes
  • The person has moved to another mail system and the old server knows it.
What to do
  • Use the forwarding address if the reply gives one, otherwise ask the person for their current address.

Usually the fault of: recipient.

Common questions.

What does 551 mean?

The mailbox is not on this server. The reply may name the address to use instead.

Will retrying fix 551?

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 551?

Use the forwarding address if the reply gives one, otherwise ask the person for their current address.

Other codes: 250 · 421 · 450 · 451 · 452 · 500 · 501 · 503 · Decode a whole bounce message

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