Hi,
Can you add an eval block to your code and try printing $@ and also $! what it prints?
You may be attempting to download a file attachment too large for your mail to handle. Email was never designed for file transfer, and therefore doesn't accomplish this efficiently. If you would like to send a large file to someone, we would recommend uploading it to your Virtual Server and making it available for download through HTTP or FTP.
Remember there will be at least two copies of any file attachments. If your virtual server does not have enough extra space to hold two copies of an email, it cannot be delivered, and if your virtual server does not have enough extra space to hold two copies of your mailbox, you cannot download the mail.
Also will these be helpful to you
http://perl.about.com/od/emailandperlscripts/l/aa042302b.htm
http://www.tek-tips.com/faqs.cfm?fid=2901
http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=196&lngWId=6
Regards