Frederick,
thank you for the reply.
Maybe I did not explain clearly enough. Let's say I have ten JPEGs. I make a new folder in Finder, call it "Pictures" or so, put the JPEGs in it and then, after writing the mail, I click "attach" and select the newly generated folder so that it will be attached. In the outgoing window of the mail I see it then as the "Pictures" folder. The recipient then gets the mail with an attachment called "pictures.zip" that calls for an unzip application in order to take a look at those JPEGs.
Now the problem is, Mail app will automatically make a zip out of it. Yes, I have "Send PC-compatible" turned on. I use, b.t.w. plain text, not formatted. Some recipients have no problems with the zip, I know, but some do have.
I want Mail to send the folder without zipping it. Making it a little bit smaller in size is (indeed only a little bit!), in many cases, not necessary and, like I wrote, often only confusing (especially when the recipient PC asks "...this is a programme, do you want it to open?- Of course, most reasonable users are afraid of those messages!).
The point is, my application is doing something that I don't want and I find no way to tell it "please, no".