It makes sense that the design converges with Firefox's, but the flame doesn't really translate the same way with Thunderbird. I never thought of the connotatio

It makes sense that the design converges with Firefox's, but the flame doesn't really translate the same way with Thunderbird. I never thought of the connotation with "firewall" before, though one could say that it's a bit unfortunate that the mail is set on fire. Firefox moved away from depicting a burning planet.