Find Spamming Account in Postfix or Plesk

This following commands sorted a list of the accounts those have the most mail in the queue:

mailq|grep ^[A-F0-9]|cut -c 42-80|sort |uniq -c|sort -n|tail
grep “status=sent” /var/log/maillog |cut -d “=” -f 2 |cut -d “>” -f 1 |cut -d “<” -f 2 |sort -n |uniq -c
grep “dovecot” /var/log/maillog |grep “Aborted login” |cut -d “,” -f 3 |cut -d “:” -f 4 |sort -n |uniq -c

If you want to find the spammer on server you can check our article here Find spammer on plesk server