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Qmail and Postfix are the email servers in Plesk. Usually, Qmail is used as the email server. Here I am explaining some commands which will help you to troubleshoot any problem with Qmail. 1, Start Qmail service # service qmail start 2, Stop qmail service # service qmail stop 3, Qmail log location in Plesk server # /usr/local/psa/var/log/maillog
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