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SMTP codes

SMTP 541 Rejected by recipient’s filter

The recipient server’s antispam rejected the message as spam.

541
Class
5xx · Permanent failure
Retried?
No, the message bounces
Defined in
RFC 5321

What to do

How it appears in a bounce

541 Rejected by recipient’s filter

Paste the full bounce into the decoder — it finds every code and recipient and says what to check.

Idea?