Looking at free email webmail for production deployment will list SquirrelMail as a functional email webmail. For real organizational functionality, it will be expected that a webmail client should not be limited to just send and receive emails. It needs to incorporate messaging, tasks, notes and calendars. Security is also a necessity and the chosen email server should have a regular updates for patches and vulnerabilities identification.
Historically, the webmail portion of the project was started by Nathan and Luke Ehresman in 1999 and is written in PHP. SquirrelMail can be employed in conjunction with a LAMP “stack”, and any other operating systems that support PHP are supported as well. The web server needs access to the IMAP server hosting the email and to an SMTP server to be able to send mails.
Squirrel Mail features include but not limited to creating and managing folders, filtering emails, changing color schemes, and use of calendars. It also includes sorting of messages capability. Surprisingly it provides a built-in spam detection even if its opensource. Its called Spam Cop which is an email spam reporting service, allowing recipients of unsolicited bulk or commercial email to report IP addresses found by SpamCop’s analysis to be senders of the spam to the abuse reporting addresses of those IP addresses.
Setting up SquirrelMail is simple which involves the following steps: download all required software, install web server and PHP (version 4.1.0 or above), install IMAP server, unpack SquirrelMail package, prepare data and attachment directories, directory access considerations and configuring SquirrelMail, and checking SquirellMail by logging in.
With all the noted SquirrelMail functionality, this webmail is recommended to organizations using basic email receiving and reply functionality.