Let me explain my suggestion in more detail.
You're having errors in the eval, and you want to trap them. The eval will trap any die and store it in $@, which you're then processing. The problem is that a warn does not get trapped by eval, it just goes to STDERR. So the error is printed to that file, and then when you test $@ you have no sign that there was a problem.
My suggestion turns warns into dies so that eval can trap them so that the code that you presented does something closer to what you say that you want. You're right that I've left warns as dies afterwards. That's fixable. In fact try the following variation of the eval and tell me whether it works better:
# create an IMAP connection
eval {
# This is the inserted line.
local $SIG{__WARN__} = sub {die @_};
$imap = Mail::IMAPClient->new(
Server => $IMAP,
User => $UNAME,
Password => $PWD,
Uid => 0,
Debug => $DEBUGGING,
) or carp "Cannot connect to $IMAP as $UNAME: $@";
};
I give you good odds that this will cause your
eval to do what you want it to do, and it won't make
warns into
dies later in your program.