A Mail User Agent (MUA), or email client, is software such as Microsoft Outlook that enables users to send and receive email.

FortiMail units support SMTP connections for sending of email by a MUA.

FortiMail units operating in server mode support POP3 and IMAP connections for retrieval of email by a MUA. For email users that prefer to use their web browsers to send and retrieve email instead of a traditional MUA, FortiMail units operating in server mode also provide FortiMail webmail.