Same error at my side
I am experiencing the same error, platform is Centos + Amavisd + Dovecot.
I see mails are properly arriving to postfix and redirected to vacation domain, but vacation mail is not sent:
to=<vacation@domain>, relay=dovecot, delay=0.16, delays=0.02/0.01/0/0.13, dsn=2.0.0, status=sent (delivered via dovecot service)
Jan 14 21:05:59 ip-10-226-109-205 postfix/pipe: 3FA9CC1F8: to=<email@example.com>, relay=vacation, delay=0.31, delays=0.02/0.02/0/0.26, dsn=2.0.0, status=sent (delivered via vacation service)
Jan 14 21:05:59 ip-10-226-109-205 postfix/qmgr: 3FA9CC1F8: removed
I have put into /etc/hosts entry for my public IP:
but it is the same.
Any ideas, anyone?