Fonant uses the following software for handling e-mail messages:

• sendmail to transfer messages.
• MailScanner to scan all messages.
• Clam-AV for virus-scanning.
• SpamAssassin for spam-filtering with additional rules from the SpamAssassin Rules Emporium (using rules_du_jour) and a few personalised custom rules.

Fonant publishes SPF records for its e-mail domains, to specify the servers that are authorised to send mail from each domain. This can help to make sending mail to domains that use SPF filtering more reliable, as well as reducing the potential for spammers to falsely use e-mail addresses.