Does OS X Mail in Leopard support message receipts?

Question

I haven't upgraded to Leopard yet...there's no compelling reason to do so for my purposes, but I can think of one reason that would make it worthwhile -- namely, if OS Mail in Leopard supports message receipts. Every message I send (in SeaMonkey's mail app) requests a "message displayed" receipt. Alas, recipients who use OS X Mail never even see the receipt request.
For all its other virtues, the lack of receipt support will forever doom OS X Mail to being a mere plaything, not for serious mail users. I mean, OF COURSE you would want to know whether your message was received...DUH! It's incomprehensible to me that Apple has excluded that feature...well, through Tiger, at least.
So, can anyone tell me whether OS X Mail in Leopard supports mail receipts? I can't find anything on the OS X Mail webpage that mentions it one way or another.
Thanks!

Answer 1

Matthew:
Of course you're correct, but floba's observation is a bullseye; I'm well aware of Thunderbird, as a SeaMonkey user (and before that, the Mozilla Suite, and before that Netscape Communicator...back to v4.75 in System 8 and 9).
No question — T'bird is a great mail application. I like SeaMonkey's mail app because of its tight integration with the Navigator browser as part of the same suite of web apps, but that's a matter of personal preference. I certainly can't fault Thunderbird's functionality. Except for browser integration (and of course the skin and layout), it has virtually all the same features that I like about SeaMonkey's mail and newgroups app.
As you might know, Mozilla Foundation (MoFo) originally promoted T'bird as a mail app that "plays nice with the browser"...by which they meant Firefox. I always thought that was a bit odd, because for integration with the browser, there has never been anything better than the evolving Communicator/Mozilla/SeaMonkey suite, in my opinion.
But it's no secret why they took that route. They wanted to break up the Mozilla Suite and repackage the browser and mail apps as standalone programs that could go head to head with Internet Explorer and Outlook Express. Firefox and T'bird are the result. They've been a huge success for MoFo, and they're fine apps in their own right. Ditto for Safari and Mail in OS X. I use Safari often. I'd use Mail more if it supported receipts.
I still give SeaMonkey the edge for my purposes, but my needs are different than most folks. I rely heavily on SeaMonkey's Composer app, which is an invaluable research tool for creating and saving annotated web pages. It's a decent site builder too...and it has been available as the excellent standalone Nvu composer for some years now.
Thanks!