[imp] only able to log in using FQDN

[Jeremy Weader]

Hi everyone,

I'm having a strange issue logging into Horde/IMP. It seems that I can only login successfully if I am accessing IMP using the fully qualified name. For example, the machine name is osangar, and the internal FQDN is osangar.int.allpropa.com.  If I type 'http://osangar.int.allpropa.com/horde/imp/login.php' into the browser, all is well and I am able to log in successfully. However, if I try to access 'http://osangar/horde/imp/login.php', I put in my un/pass, click login, and after a few seconds the login page reloads, showing no errors. 

Authentication is set up to pass through to IMP, which is authenticating against my IMAP server. In both cases I can see a successfull authentication in the mail server logs, so I know that part is working. Has anyone experienced this before, or any suggestions on where to check? Thanks.

/Jeremy