Customize Mail.app X-Header

drscream — Fri, 10 Jul 2009 09:38:20 +0000

It is possible to add custom headers to mails your are sending with Mail.app. You need to open the Terminal.app and use the following commands.

defaults write com.apple.mail UserHeaders '{
"X-What-Happen" = "Somebody set up us the bomb.";
"X-Accept-Language" = "de, en";
}'

To read the content of your UserHeaders:

defaults read com.apple.mail UserHeaders

To delete the content of your UserHeaders:

defaults delete com.apple.mail UserHeaders

Don’t show HTML Emails in mail.app

drscream — Sat, 17 Nov 2007 11:04:08 +0000

I don’t like mail.app … but what i really hate are HTML Emails. So we can turn it off!

Execute the following command in the console and all your email will now appear in plain text:


defaults write com.apple.mail PreferPlainText -bool TRUE