mail server

>Hello PLUG,
>    My company is currently using an NT based mail server called Post.Office
>from software.com.  To be truthful, it stinks and is a resource hog.  They
>have agreed to let me install a Linux based mail server.  I do, however,
>have a bit of newbieitis when it comes to mail servers on linux.  Will
>sendmail be able to replace our server?  Can it to POP and SMTP?  We have
>about 200 accounts to move over, will sendmail be able to handle them all??
>If not, are there any other mail servers for Linux that can do all of the
>above?  Thanks a thousand times in advance.