how can i access or add into my mail server using PHP ($_post['email'];
the only thing you need is the function "mail" (read the manual for detailled information)
In case you're lazy... [man]mail()[/man]
can i use mail() function to access my smtp server like reading mails, creating mail account?
The smtp protocoll is used to send mails. What you asked for is possible with imap-mail. Check if your provider support IMAP. You can look for web-mail-clients on www.hotscripts.com
But only use IMAP if your server is running IMAP (sounds a bit obv, but I've been asked bout that before).