The red is a bug in the current version of Thunderbird and shouldn't really affect the sending of messages.

The blank content is somewhat mysterious though. Are these messages straight-up "composed by you" creations, or are they made up of forwarded or copy'n'pasted material?

If you'd care to send me one, I'd be interested to see what it contains.

xenos at gmx dot co dot uk

SedonaKelly said

I'm not able to put an address in that doesn't show up red. The addresses are in my address book. They send however the recipient receives a blank email.