Postfix sending spam

[meteadan]

My server (postfix) is sending spam from a local user account which no longer exists in the server.
I checked vhosts account and verified that no phpmail () function is sending those emails.
My relay is not open.
I don't where these emails are coming from.
All the emails sender address is a local email account with external ip addresses. I have disabled the email account and disabled the smtp service for that domain and yet the email continues.
A lot of emails are building up in the deferred mail queue.
Please someone HELP...

 

[udaythapa]

Can any one help me!

Plesk server , centos 6.x , plesk 11.0.9, postifx mta ... i am fade up with automatic spam generating from unknown email id yahoo, etc with unknown ip address.
i checked with PHP script got from plesk farum , not detected ........due to this again and again ip's getting black listed .
all email ids have complex password.
??/