Just a few observations for this thread may confuse some who are looking for basic email support via Parallels.
A simple clickable link for an email address does work in PD4.
As stated above, set Mail to the default reader and set PD4 to use Mail.
I utilize this with Excel in XP in my BootCamp VM where I have simple lists of email recipients.
On the other hand, if I have a VB6 routine that calls up Outlook when a link is clicked, sets up the email with a subject, content text, and attaches a file, Outlook is what comes up. I wouldn't want it any other way.
The software package in question, RentMaster, is a pretty neat package that integrates many Windows software packages. It probably depends on Outlook for this integration and is most likley written to specifically call up Outlook so that various attachments can be sent at the same time. The software developer seems open to new features and might be the best source for integration outside of Windows. The combination of PD4 and RentMaster would serve to expand their user base outside of Windows and would save them the hassle of writing for a different OS.
A workaround might be to have a copy of the email sent to yourself which would be available view in Mail, although Outlook would have to be set up with the proper server config information and would be the primary record keeper of what is sent. At least Outlook would only contain a history of email sent from RentMaster which may not be a bad idea.