I've added some email accounts with the help of Plesk. The strange thing is I can't receive any emails. The mail service is active. And sending mails works without any problems.
The mailer-daemon message is: "Sorry, no mailbox here by that name." The same message appears in the syslog file.
All the files within the qmail directory (/var/qmail/mailnames/domain.com) have been automatically created by Plesk. They seem to be ok.
How can I fix this problem?