Thanks again for the reply Andreas.
Don't you just love undocumented features?! I'm glad to see that I am not going blind.
Although I found that your script works great for sending HTML emails for the majority of target clients, I found there are a couple that don't like the formating: i,e. Hotmail in particular displays the HTML content as raw source. Which is way irritating (typical MS issues), and hence the need for Alternative Text.
I did find a commercial bulk mailer for OS X, called MaxBulk Mailer from MAX Programming, that allows for the alternative plain text section, and it formats the html section in a fashion that Hotmail likes. The main feature I love about Max Bulk Mail is the management of large distribution lists: it breaks up the list into chunks (say 90 people) and spreads out sending those chunks over time (i.e. at 5 hr intervals, send the next chunk). Since, as I found out, Most ISPs have limits on how may people you can send a single mail to (my ISP is 99) and a maximum of 1000 emails a day (to prevent spamming), these features were perfect for a massive family newsletter I had to send out this week.
Although, MaxBulk Mailer is commercial ($49US), it does not expire, but adds a tag to the end of the emails stating that the email was sent with an unregistered MaxBulk Mailer. Hey, I can live with that for large mailings I do, maybe once a year! The one thing I don't like is it is really flakey for importing email list. You can drag and drop from address book, and names and e-mails format perfectly. But if you try to bring in lists from any other source, including text files, you have to spend a day making sure the headers and the format is just right. It would be nice if there was a way to remap fields on the fly, which nobody seems to to do, including Entourage X, that I have found anyway. Such an obvious feature to be universally ignored IMO.
Anyway, enough griping...
Thanks again for the info. That and going through the script, gave me a good understanding of how HTML email works. Without it, I would never have know what to look for in a mailer.
Here's hoping the Mail 10.4 addresses a need for HTML e-mail, and maybe has these very useful features properly documented.
Gary