Knowing that I'm beating a dead horse, here, "don't do it!"

As noted above, there are many, many arguements against using html in mail, and precious few (IMO) in favor of using it.

But, more to the point
This is perlmonks; and a quick look at How do I post a question effectively? suggests several improvements to your question

• Show us some (Perl} code (or at least show us your mail.pl code.)
• Tell us why what appears to be financial data needs to be transmitted as a webpage.

And,

• Welcome to the Monastery, and...
• for whatever its worth, why don't you create an account here?

Update: fixed missing close_paren, missing period