You haven't told us whether a file actually exists at the location that $Form{attachment} outputs. The -f test checks for that. As T: sounds like a (remote) network drive, it could also be that the webserver user (and thus, likely the Windmail user) don't have access to that network resource. A second test from within Perl could confirm that, as could obtaining the Windmail logs.

Of course, you can still simply copy MIME::Lite into your script, no matter how much reluctance you show.

Ah I see, oh yes it definitely exists, I'm actually browsing to it in the Web form, but I've also tried hardcoding a file name into the script rather than using $attachment and I still have the same problem (and the hardcoded file name was in the same folder on the same drive as the script)

MIME::Lite won't work - it's not a module that my Perl installation has ;-(
Never knowingly obfuscated

Corion said: "Of course, you can still simply copy MIME::Lite into your script, no matter how much reluctance you show.", as well as having told this to you in the CB before you posted your question.

You seem to either be ignoring this advice or you don't understand what you have repeatedly been told. MIME::Lite is not a core module, so you are going to have to:

A) Install it (see the Installing Modules from the tutorials section of this site)
B) Do as you have been told and use the source of MIME::Lite within your own script.

Martin

Copy code from http://search.cpan.org/src/RJBS/MIME-Lite-3.021/lib/MIME/Lite.pm and paste it into your program