Free mailservers software for windows

SpamPal sits between your email program and your mailbox, checking your email as you retrieve it.
Any emails that SpamPal will consider to be spam are "tagged" with a special header; you will be able to easily configure your email client to filter anything with this header into a separate folder and your spam wont be mixed up with the rest of your emails anymore.
Features:
- Check your mail against the freely-usable DNSBL lists (aka "blocking lists") of your choice.
- The list of available DNSBL services is automatically updated, so new DNSBL lists can be used as they appear!
- Whitelist the email addresses of your friends and family so that mail from them will never be tagged as spam!
- Dont agree with a listing in a DNSBL list? You can whitelist entire netblocks so youll never be troubled by that listing again!
- Do you think part of the Internet should be blocked that isnt in a DNSBL list? Add it to the local blacklist and all mail from it will be tagged as spam! You can blacklist email addresses or entire netblocks!
- People and mailservers with whom you correspond frequently are Automatically Whitelisted - without you having to lift a finger!
- More than one mailbox? Dont worry, SpamPal supports multiple POP3 servers.
- Supports APOP authentication!
- Can filter IMAP4 mailboxes!
- Can even protect an SMTP connection!
- Unobtrusive! Once installed, SpamPal sits in your system tray and you can forget all about it - except spam wont be causing you so much trouble!
- Multi-language support! Use SpamPal in English, German, French, Italian or Russian
- Subject Line Tagging. As well as its special header, SpamPal can put "**SPAM**" in the subject of spam messages.
- And if all this isnt enough, you can extend SpamPal with third-party Plug-ins!
- SpamPal will not be able to detect all of your spam. However, I think it will detect enough to make a considerable difference!