User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:64.0) Gecko/20100101 Firefox/64.0 Steps to reproduce: I attempt to "Drag and Drop" or "Insert" a picture, (jpeg,gif etc), into the body of a new email, then send to recipients. Actual results: Text in the body of emails gets sent and received normally. Pictures pasted/inserted into body of emails are not sent. Expected results: Pictures should be sent to, and displayed to recipients.

Looks like a configuration error. For the last complaint we had, see bug 1510134, in particular see bug 1510134 comment #17. Check: Tools > Options, Compisition, "Send Options" (button) (or on Mac, somewhere in Preferences). Make sure you're not sending plain text to recipients which are not classified as being able to receive HTML. Richard, just to be double sure: Sending of embedded pictures on Mac works, right? Bug 1514797 was also for Mac.

Tested with TB 60.4 on Mac and both, "Drag and Drop" and "Insert" a picture, are sent with the picture included.