Cannot sent message via webmail: “User unknown in virtual alias table”

If Postfix files are corrupted completely, or empty: Create a backup of the current configuration: ~# cp -Rp /var/spool/postfix/plesk /var/spool/postfix/plesk.backup Remove redundant records from the Postfix database: ~# cd /var/spool/postfix/plesk/ ~# for db_file in virtual virtual_domains ; do ls -1 –color=never /var/qmail/mailnames > /tmp/domains.txt hostname -f >> /tmp/domains.txt postmap -s /var/spool/postfix/plesk/$db_file > /tmp/${db_file}_temp grep -f …