Plesk uses qmail as email server. qmail is a very secure and efficient email server. Big email services like Yahoo, Gmail uses qmail as mail server. By default qmail support only local system users, that is users created on *nix, authonticated with /etc/passwd

qmail support multiple domains (virtual host) with vpopmail.

To change password of an email address

/home/vpopmail/bin/vpasswd [email protected] 123456

This will reset password of email address [email protected] to 123456

To know information about an email account

# /home/vpopmail/bin/vuserinfo [email protected]
name: sherry
passwd: $1$9la81$Ncg2VVffGMRWcMlqaDl14/
clear passwd: 123456
uid: 1
gid: 0
all services available
dir: /home/vpopmail/domains/bizhat.com/sherry
quota: NOQUOTA
usage: NOQUOTA
last auth: Sun Sep 25 18:56:21 2005
last auth ip: 68.218.133.50
#