SMTP 0<001501c4db9b$db8b2680$2d01a8c0@ryand9v889t9uc> .X-Intermail-Unknown-MIME-Type=unparsedmessage Header2: ## $ cat sample.txt | perl -wnl -e '/\.X\-Intermail\-Unknown\-MIME\-Type\=unparsedmessag(e.*)/s and print $1;' e