Cannot cancel send and other concerns

Question

I use Mac Mail with IMAP gmail, usually it works well. Today I was composing a message, and having learned my lesson previously I waited until the last minute to apply the attachment I intended to send. Unfortunately I mis-clicked and attached the 50MB wav file insted of the 5MB mp3. It immediately started uploading the 50MB file to my drafts folder. I have repeatedly clicked on the cancel send button in the lower left without luck. In fact, the cancel send button has never worked for me when uploading a draft.
Now I'm waiting for gmail to choke on the file which is five times larger than the server will accept since the last time I force-quit mail in the middle of an operation it totally munged my inbox.
I have two questions: What's the deal with the cancel send button? And is there an option somewhere which will prevent the mail application from uploading attachments over a certain (hopefully configurable) size to the drafts folder?
I like the fact that it uploads drafts to the server, but I don't want it to monopolize my upstream bandwidth. Especially if I change my mind about an attachment or mis-click.

Answer 1

Your questions have been answered haven't they?
You answered the first yourself...
What's the deal with the cancel send button?
The cancel button is the little circle with an x next to the status bar while uploading, usually you don't see it for very long unless you're sending a pretty big file or on a slow connection. It's in the "Mail Activity" pane which doesn't appear by default.
And the second Mulder answered quite well...
And is there an option somewhere which will prevent the mail application from uploading attachments over a certain (hopefully configurable) size to the drafts folder?
No, there's no such option
You could also take the account offline in Mail until you've got it right and chosen the correct attachment, or you could turn off the internet connection to stop Mail communicating with the server. You could also install a different email client, like Eudora for example, that does have an attachment size limit AFAIK.