exim.ro

Basic SMTP reply code · RFC 5321

251 User not local, will forward

The recipient is not on this server, but the message will be forwarded.

Have the whole error message?

The whole bounce, a line like 550 5.7.26 … or the DSN fields (Status:, Diagnostic-Code:). At most 64 KB.

The text is read in memory only and not kept.

Sources: RFC 5321 · RFC 3463 · RFC 3464 · IANA · Gmail · Microsoft 365 · read on 26 September 2026