I think I found a serious problem when reading mail
with attackments or links.
I was working on an XML serializer that saves PHP
session information in a usable form of XML. I found
that Squirrelmail has some self referencing variables
causing endless recursion and eventual crash.
The recursion looks like this:
messages->1122385483->8589->entities->1->parent->entities
The "entities" item recurses forever in my code, and I
think it also nukes PHP and causes the attackment errors.
My session serializer can be found at
www.mohawksoft.org, and can be downloaded via CVS. The
project name is xmldbx.