I'm having problems e-mailing image files (specifically JPEGs - mainly ones I create/edit in Photoshop) from Mail.app on OSX 10.4.8 to Windows users who have Photoshop installed. If I just attach the file to an e-mail, the Windows user often gets a message saying "Unable to open due to unknown or invalid jpeg marker type found" when they try and open the JPEG in Photoshop (they haven't tried it elsewhere). But, I saved it as a JPEG in Photoshop on my mac! This isn't just my computer, as I've heard of others with this problem. The only way around it is to click the "Send as Windows Friendly Attachment", but the Help pages advise against doing this for Mac users. I don't want to have to e-mail people and ask them "Do you have a Mac or a Windows-based computer?" before I send them a file. Am I doing something wrong in Photoshop that's preventing Windows users from opening my files?