I’ve bonked my head on a wall for a while helping people to send multiple attachments with Mail.app in Mac OS X to an AOL email account.   I think this is a working solution, although it is not very elegant in the Mac-sense. Before you read the solution, here’s the problem, as documented by AOL: http://members.aol.com/adamkb/aol/mailfaq/#attachmentsThe workaround is a cute two-step procedure if you have the appropriate software installed. So, if you want to attach a single file to an email message going to an AOL user, try the following:1) The attachment must be the very last thing in the message. Before attaching files, place the cursor at the very end of the mail message (keep using the down and right arrows to make sure the cursor is at the end of the document or in Mail, just choose Edit->Attachments->Always Insert Attachments at End of Message); and2) Erase the resource fork from your file before sending it by right clicking on it and choosing “GrimRipper” from your contextual menu.Before you try this for the first time, you’ll need to install “GrimRipper” using the link below (to install, download the file from the bottom of the linked webpage, and from the disk image on your desktop open the file called “Install GrimRipperCM”, and click the blue buttons whenever you’re prompted by the installation):

http://www.abracode.com/free/cmworkshop/grim_ripper.html

What’s going on behind the scenes? By doing these steps, Mail should be able to skip the appledouble encoding when you send an attachment and send a single base64 encoded data fork (i.e. your attached file)… Please keep me posted if this works for you. I believe you’ll still only be able to send one attachment at a time.