Mailman 500 error

[BitSprocket]

All,

Getting a server 500 error when trying to access the mailman for my domain. Here's what I know so far:

1) the error in the site's error log says:

Premature end of script headers: admin
suexec policy violation: see suexec log for more details

2) I haven't been able to find a suexec log anywhere

3) The initial email is being sent but the links inside point to the servers name instead of the site url (ie. webserver.mydomain.com instead of www.mydomain.com)

A little googling indicates that mailman is not a fan of suexec but I don't know if that matters.