[imp] IMP causing Error 406 when sending mail

[Brian Voils]

For some reason, IMP is causing an HTTP Error 406 when sending mail to
any AOL (@aol.com) e-mail address.  It does this from any login I use,
but only to AOL accounts.  It works fine for other recipients.  I know
the problem is with my installation of IMP because my host has their
own installation (which is very cumbersome to login to) which does not
exhibit this problem.  I imagine it's a corrupt file somewhere, but
it's odd it only errors on AOL addresses.
Any ideas what's going on?

It's installed on a shared server, and I don't have shell access.
They do have a terrific helpdesk, however, and can do just about
anything on the shell for you, if needed.  I have FTP access and do
have filesystem access, however.

Anyways ...

Version Information:
IMP Version 3.2.3
Horde Version 2.2.5
PHP Version 4.3.11
Apache/1.3.33 (Unix) mod_auth_passthrough/1.8 mod_log_bytes/1.2
mod_bwlimited/1.4 PHP/4.3.11 FrontPage/5.0.2.2635 mod_ssl/2.8.22
OpenSSL/0.9.7a
Linux server54 2.4.21-32.0.1.ELsmp #1 SMP Wed May 25 14:26:33 EDT 2005 i686
--
Brian Voils