Intermittent mailgate problems

Hive Mind,

I am getting errors in my RT log that I can’t figure out.
My guess would be that some recent changes in our mail
environment (Exchange) are tickling a bug in RT. (Or
the bug that is Exchange - if you see things my way;
and I am pretty sure that you do.)

Here is the error:

Dec 12 11:40:11 usvwoaahs501v RT: Couldn’t load module ‘RT::Interface::email::’: Can’t locate RT/Interface/Email/.pm in @INC (@INC contains: /opt/rt3/local/lib /opt/rt3/lib /usr/local/lib/perl5/5.8.4/i686-linux /usr/local/lib/perl5/5.8.4 /usr/local/lib/perl5/site_perl/5.8.4/i686-linux /usr/local/lib/perl5/site_perl/5.8.4 /usr/local/lib/perl5/site_perl . /usr/local/apache/ /usr/local/apache/lib/perl) at (eval 2950) line 1. Stack: [(eval 2950):1] [/opt/rt3/share/html/REST/1.0/NoAuth/mail-gateway:56] (/opt/rt3/lib/RT/Interface/

I don’t have any special code in this area of RT. I have
never touched RT::MailPlugins.

Has anyone seen this before?