Mail forwarding error in Plesk: unable to execute /usr/sbin/postdrop -r: Success 4.2.1 Message can not be delivered at this time

Symptoms

• Email is not forwarded to address set in Plesk > Domains > example.com > Mail Settings > Email Addresses > [email protected] > Forwarding;

• /var/log/maillog contains following error:

  to=[email protected], relay=plesk_virtual, delay=1.7, delays=0.45/0.01/0/1.3, dsn=4.3.0, status=deferred (temporary failure. Command output: sendmail: fatal: execvp /usr/sbin/postdrop: Permission denied sendmail: warning: command "/usr/sbin/postdrop -r" exited with status 1 sendmail: fatal: [email protected]: unable to execute /usr/sbin/postdrop -r: Success 4.2.1 Message can not be delivered at this time

Cause

Wrong permissions are set on Postfix files.

Resolution

1. Connect to the server via SSH

2. Fix Postfix executable files’ permissions:

   # /usr/sbin/postfix set-permissions

If it doesn’t help set below ownership and permissions:

# chmod 2550 /usr/sbin/postdrop
# chown root:postdrop /usr/sbin/postdrop