SquirrelMail
Hosting

SquirrelMail is, frankly, a museum piece. It was the default webmail client on something like half the shared hosting accounts in the world for a stretch of the 2000s, and a generation of small business owners learned what webmail was through SquirrelMail's grey-and-blue interface. I have a lot of affection for it. I do not recommend it for anything new.

What works well: SquirrelMail still does what it always did. It connects to an IMAP server, it shows you your inbox in a basic three-pane layout, it lets you reply, forward, and attach files, and it does this on basically any PHP version without requiring a database. If you have a SquirrelMail install that's been running since 2008 and a small team that's used to it, the install will probably keep working for as long as you don't move PHP versions aggressively.

What's annoying, and this matters: the project has been in maintenance-only mode since 2013. There is no active feature development. The interface looks like it's from 2002 because it is. There's no two-factor authentication option that I'd trust today, the rendering of modern HTML emails is poor, and the attachment handling has limits that haven't been raised in over a decade. On mobile, the experience is genuinely bad. Modern phishing emails render in ways the old HTML rendering can't show clearly, which makes user awareness training harder.

"I'll keep SquirrelMail installs running for customers who genuinely need to. I won't recommend it for anything new. If you're starting a webmail deployment in 2026, install Roundcube instead. If you're sitting on a SquirrelMail install, plan a migration before something forces it on you."

Mark McNeece, Founder, 365i Hosting

On hosting: SquirrelMail is happy on our shared hosting from £5.99/mo. It uses almost no memory, has no database to maintain, and the file footprint is tiny. PHP 8.3 mostly works, but a few of the older plug-ins have not been updated for PHP 8.x at all and will throw warnings or errors. We can usually pin a specific PHP version per site if you need that, and we keep PHP 7.4 available for legacy applications precisely because of cases like this.

The migration path I'd suggest, if you're sitting on SquirrelMail today: install standalone Roundcube alongside SquirrelMail, point both at the same IMAP server, give your team a fortnight to try Roundcube, then retire SquirrelMail. The mailboxes themselves don't move because they're on the IMAP server, only the webmail interface changes. We can do the parallel install for you free of charge as part of our migration service. Most migrations take two to four working hours including a brief training session for the staff who use it daily.

If you're going to keep SquirrelMail running, the things to do regularly: keep PHP version pinned to something the install actually works on, keep the install path behind HTTPS (free SSL is included), apply any security advisories that the small remaining maintainer team publishes, and consider IP-restricting the admin URL if it's only used from one or two offices. Otherwise, plan to migrate.