autoresponder. need help

[deadpan]

I have recently added an autoresponder to be used by sendmail.. everything seems to be working fine except it only works with web-based mail as the message sent is in html format .. i have looked over the script a number of times (mailback.pl) and it makes no mention of the emial format so i was wondering if i need to configure something in sendmail being new to both sendmail and perl im really in need of some help..<br>
Thanks in advance for any tips