Checking process stack in Linux

Generally the command to show the process stack is ps auwx

Since this spews out every single process running and we want to prune it down to show specific processes use grep as follows:

To show pop3 processes:
ps auwx | grep pop3

IMAP
ps auwx | grep imap

HTTPD:
ps auwx | grep httpd

POSTGRESQL
ps auwx | grep postgres

SENDMAIL
ps auwx | grep sendmail

and so on....