- Plesk for Linux
The following entries are found in
CONFIG_TEXT: localhost postfix/smtp: 8F5F71040FA7: firstname.lastname@example.org, relay=mx.somerelay.com[203.0.113.2]:25, delay=19, delays=0.02/0.01/0.19/19, dsn=5.0.0, status=bounced (host mx.somerelay.com[203.0.113.200] said: 550-Verification failed for <email@example.com> 550-Unrouteable address 550 Sender verify failed (in reply to RCPT TO command))
Server notifications are not sent to the admin mailbox;
Mail gets blocked because the domain name of the sender is not a FQDN (Fully Qualified Domain Name).
Sender's domain name is taken from the server hostname.
Change server hostname according to this guide: How to change or get a server hostname on Plesk server