Addresses already in Address Book display in red in the TO field
When typing the start of a name (address) in any of TO, CC or BCC fields, names already in the Address Book, Thunderbird suggests options as usual but once a name is selected, it sometimes displays in red, sometimes in black, and sometimes start off in red and when I click on the one I want or press enter it ends up displaying in black.
Wšě wotmołwy (1)
This is a reported bug. You could add your 'vote' to this bug, but you do need to register first or logon. the vote link is in the top section: Importance: -- normal with 6 votes (vote)
https://bugzilla.mozilla.org/show_bug.cgi?id=1042561
The red lettering does not cause any sending issue.