I recently encountered a problem, however, where despite having set the account-specific preferences to not quote the original email in a reply, it was doing it anyway. No matter what I did or tweaked, Postbox would automatically included the quoted message. It was pretty annoying, as I had to delete everything manually, and for emails that include a lot of HTML that can be a pain. So if you have issues with your Postbox preferences too, you can do what I did ($ refers to command link prompt in the terminal)
- Make sure preferences are set to how you want them to behave (e.g. quote message on reply box in unchecked) and the close Postbox.
- Navigate to the Postbox preference file location: $ cd /Users/username/Library/Application\ Support/Postbox/Profiles/random_characters.
default/ - save a backup: $ cp prefs.js prefs.js.backup
- open prefs.js (I just did $ open prefs.js to open it in xcode)
- if your problem is quoting on reply, find the: user_pref("mail.identity.id4.reply_quoting_style", 2) and set it to user_pref("mail.identity.id4.reply_quoting_style", 0)
- save the file and reopen Postbox and it should be fixed
You can scroll through and pretty easily figure out what the different preferences are from there name, just be sure that you have a backup in case you mess something up. Worst case scenario you just rename your prefs.js.backup back to prefs.js and you're good to go