Can you use HTML signature in webmail/SquirrelMail?

I see an option for "Show HTML Version by Default" which I checked, but when I paste in my HTML signature from Apple Mail it still looks like plain text in Options/Personal/Signature. Just to test I copied the same thing into TextEdit and the HTML was all there...

I got on the SquirrelMail IRC and apparently you need a plug-in to support HTML composition?! It looks like this is the plug-in:

http://squirrelmail.org/plugin_view.php?id=209

Last updated in 2005... not sure why this needs to be bolted on in 2009. I'm hoping it allows my users to setup HTML signatures.

I installed html_mail and have tried copying and pasting my HTML signature as-is (meaning HTML rendered) from Apple Mail and copying and pasting my signature in HTML code and neither one results in the HTML signature displaying as HTML in the composition window. In the latter case, I just get all the raw HTML code in the compose window.

Has anyone got HTML signatures working in the OS X Server webmail??

Both... if I do a copy/paste of the rendered HTML from the Signature setting in Apple Mail to the Signature option in SquirrelMail, all I get is plain text in the SquirrelMail Signature option and in the composition window.

If I copy the HTML source from TextWrangler into the Signature option in SquirrelMail, I see the HTML source both in the Signature option and in the composition window. (I sent a test email to myself and verified the recipient also sees HTML source, not rendered HTML.)

I guess I'm still trying to figure out if HTML signatures are possible with SquirrelMail, I haven't been able to find a definitive answer in the docs or their mailing list. They seem to have an anti-HTML fascination when it comes to email, which I understood and even agreed to at one time, but it's 2009...