Hm, the only thing I can see that MIGHT be an issue is in the chomps. From your values assigned to $filesenders and $fileaddrlist in the first two line, my guess is that you are on a Windows system. Windows uses two characters for its 'end of line character', these being "\r\n" IIRC, whereas Unix uses one, "\n". I am unfamiliar with the Windows implementations of Perl, but I wonder if the chomps are taking off both characters, or just the \n, and if those 'spaces' are actually return characters, aka \r.

Just a thought.