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  3. NOQUEUE: reject: RCPT from mail.gimitec.com[::1]: 451 4.3.5 : Client host rejected: Server configuration problem;

NOQUEUE: reject: RCPT from mail.gimitec.com[::1]: 451 4.3.5 : Client host rejected: Server configuration problem;

August 1, 2026 cli

Error: NOQUEUE: reject: RCPT from mail.gimitec.com[::1]: 451 4.3.5 : Client host rejected: Server configuration problem;

How to solve as described in this website:
> https://www.experts-exchange.com/questions/24071333/Postfix-configuration-error-451-4-3-5-Server-configuration-problem.html

removed "check_policy_service unix:private/policy" from smtpd_recipient_restrictions in my main.cf

and in our case is


removed "check_policy_service unix:private/asnblocker" from smtpd_recipient_restrictions in my main.cf

Tal