Free mail server software

Here are some free mail server software options:

  1. Postfix: A popular open-source mail transfer agent (MTA) that can be used as a mail server. It's highly customizable and scalable.
  2. Sendmail: Another popular open-source MTA that can be used as a mail server. It's been around for a long time and has a large user base.
  3. OpenSMTPD: A free and open-source MTA that's designed to be secure and easy to use. It's a good option for small to medium-sized mail servers.
  4. Exim: A free and open-source MTA that's known for its reliability and flexibility. It's a good option for large-scale mail servers.
  5. Zimbra: A free and open-source mail server software that's designed for small to medium-sized businesses. It includes features like calendar, contacts, and collaboration tools.
  6. iRedMail: A free and open-source mail server software that's designed for small to medium-sized businesses. It's easy to install and configure, and includes features like spam and virus filtering.
  7. Mail-in-a-Box: A free and open-source mail server software that's designed for small to medium-sized businesses. It includes features like email hosting, calendar, and contacts.
  8. Mailserver: A free and open-source mail server software that's designed for small to medium-sized businesses. It includes features like email hosting, calendar, and contacts.
  9. OpenMail: A free and open-source mail server software that's designed for small to medium-sized businesses. It includes features like email hosting, calendar, and contacts.
  10. MailScanner: A free and open-source mail server software that's designed for small to medium-sized businesses. It includes features like spam and virus filtering, and is easy to install and configure.

Please note that while these software options are free, they may require some technical expertise to set up and configure. Additionally, some of these options may have limitations or restrictions compared to commercial mail server software.