Solution 1:

I'm currently using the free hMailServer for SMTP, POP3, and IMAP. It has been pretty solid in the couple years that I've been using it. I've run it on Windows 2003 R2 and Windows 2008 Standard and Enterprise. I'm using SquirrelMail for webmail. This is PHP, but it wasn't that hard to setup. This is free as well.

The best commercial experience that I had with a non-Exchange server was MDaemon from Alt-N Technologies. It has the best OWA like UI, and it has a connector for Outlook, so that it thinks it is an Exchange server. The price for this server is not as much as others, but still too much for me.

There are several other email servers:

Open Source/Free

  • Zimbra - http://www.zimbra.com/
  • MailEnable Standard - http://www.mailenable.com/

Commercial

  • Kerio MailServer - http://www.kerio.com/mailserver
  • MailEnable Professional or above - http://www.mailenable.com/
  • Softtalk Mail Server (Workgroup Mail Server) - http://www.softalkltd.com/products/workgroupmail/

There are many more servers out there. The ones I listed here are the ones I had tried at one point in the past.

Solution 2:

Server 2008 does not include any built in features for POP or IMAP, the only mail component you get is the SMTP server available for IIS.

There are a number of mail servers available for server 2008, unfortunately there aren't many that are open source.

Free

  • hMailServer - as you already said it does not offer a web mail interface, but you could use something like Horde or Roundcube, which are open source, to give you your web mail interface.

  • SmarterMail - this offers a fully functional free version for less than 10 user.

  • Mailenable - Free standard edition, paid for enterprise edition

Paid For

  • Kerio Mail Server
  • MDaemon
  • Softalk Mail Server

Solution 3:

there is another tool that replaces the missing Microsoft POP3 Server in Windows 2008. Visendo SMTP Extender is available as a free community edition and a plus edition, which you can use for free for a demo period of 30 days.

Solution 4:

The price difference from a Server 2008 Standard and SBS 2008 Standard (which includes Exchange and 5 user licenses) is tiny in my opinion ^^