Well. It is a long and boring story, but in short I am having issues with the 3 E-Mail clients I have used on my Mac.
MAIL
I initially used Mail, but I really don't like the way in which it handles attachments. Plus, I was initially on a dial-up modem and any attachment over about 100 kb would fail to send. At least that was the error message I got. The e-mails went through, but Mail would always give me a failure to send message. So I had to BCC myself on everything to make sure I got it.
Once I switched to broadband this problem stopped, but I still didn't like the way it handled attachments.
Entourage
When I bought Office I thought I would try out Entourage. I really like the way this app works and was very happy until the DB that powers it broke. So for a couple of days I was stranded and had to return to Mail as it was the only e-mail client I had which still worked. When I opened it up there were hundreds of e-mails that Entourage had not downloaded from my server.
This really freaked me out so I then tried Thunderbird.
Thunderbird
This is a software I like, but it seems very buggy. When replying to e-mails if I misspell a word it will move the cursor into the reply e-mail and I find myself typing in the middle of it.
So I decided to switch back to Entourage, but I have just found some more e-mails that have arrived in the last 24 hours that it did not download. Such as the one telling me you had posted in this thread.
So I think I will just have to put up with the way in which Mail handles attachments and hope that Mac changes it in a future release.
Thanks for you time, support and offers of help.