This was posted on myezserver.com, but received no replies the last couple of days.  I am hoping someone in this forum might have given this a try.  twiggi we are running is a paid version, but you apparantly get 1 incident support and I wasted it thinking you got an hour's worth of support.  TIA for any input.
---------------
I've been running twiggi 1.10.13 for about 2 weeks now. Custom settings are: auth=forms, imap_server=10.21.1.16 (the main sme server). It's been testing fine with a handful of users  . Now, as I am getting ready to roll this out for general use, I found that the login is not working properly  . The only way I could get login to work is by setting the imap_server back to localhost. 
Can anyone explain the login process when you are configured for a separate imap_server? Does twiggi authenticate against the local account first, then against the imap_server? Or, the imap_server alone? 
I have successfully tested phpgroupware for a similar setup, but my users prefer twiggi for its simplicity and clean interface. Any input would be greatly appreciated. 
Thanks, 
Jean