Rt-1-3-94 -- not sending mail

RT-1.3.94 isn’t sending mail. Autoreply makes it, but correspondence with
requestor/owner just won’t go.

I’m not getting any errors in the httpd or maillog, but here’s the error
from RT’s logs:

Use of uninitialized value at
/usr/lib/perl5/site_perl/5.005/DBIx/SearchBuilder.pm line 893, chunk
19.
now requiring RT::Condition::AnyTransaction
RT::Transaction=HASH(0x874b87c): Checking condition OnCreate…
RT::Transaction=HASH(0x874b87c): Matches condition OnCreate…
now requiring RT::Action::Autoreply
RT::Transaction=HASH(0x874b87c): Prepared AutoreplyToRequestor
Use of uninitialized value at /www/helpdesk/lib/RT/Action/SendEmail.pm line
84, chunk 19.
Use of uninitialized value at /www/helpdesk/lib/RT/Action/SendEmail.pm line
86, chunk 19.
Use of uninitialized value at /www/helpdesk/lib/RT/Action/SendEmail.pm line
106, chunk 19.
Net::SMTP: Bad hostname ‘mailhost’ at blib/lib/Mail/Util.pm (autosplit into
blib/lib/auto/Mail/Util/maildomain.al) line 176
RT::Transaction=HASH(0x874b87c): Committed AutoreplyToRequestor
now requiring RT::Condition::AnyTransaction
RT::Transaction=HASH(0x874b87c): Checking condition OnCreate…
RT::Transaction=HASH(0x874b87c): Matches condition OnCreate…
now requiring RT::Action::Notify
RT::Transaction=HASH(0x874b87c): Prepared NotifyAdminWatchers
RT::Transaction=HASH(0x874b87c): Committed NotifyAdminWatchers
Use of uninitialized value at
/usr/lib/perl5/site_perl/5.005/DBIx/SearchBuilder/Record/Cachable.pm line
136.
Ticket 141 created in queue ‘general’

Here’s my testdeps:

Checking for DBI 1.16 …found
Checking for DBIx::DataSource 0.02 …found
Checking for DBIx::SearchBuilder 0.38 …found
Checking for HTML::Entities…found
Checking for MLDBM…found
Checking for Net::Domain…found
Checking for Net::SMTP…found
Checking for Params::Validate 0.02 …found
Checking for HTML::Mason 0.896 …found
Checking for CGI::Cookie 1.06 …found
Checking for Apache::Session 1.53 …found
Checking for Date::Parse…found
Checking for Date::Format…found
Checking for MIME::Entity 5.108 …found
Checking for Mail::Mailer 1.20 …found
Checking for Getopt::Long 2.24 …found
Checking for Tie::IxHash…found
Checking for Text::Wrapper…found
Checking for Text::Template…found
Checking for File::Spec 0.8 …found
Checking for Errno…found
Checking for File::Temp…found
Checking for Log::Dispatch 1.6 …found
Checking for DBD::mysql 2.0416 …found