http://sn.1w6.org/file/bobjonkman-20150907T055014-9kvlcrx.html

I get the same Enigmail warning message. I wish there was a way to default to allowing long lines, since that's how I always send messages. As long as Enigmail hashes the message the way it's sent, then any problems are at the client end (which should compare the hash to the received content before rendering it for display -- if the receiver compares the hash to a message that's been modified for display, *of course* the signature will fail!