alias emailattach 'echo "Message Body" | mutt -a !:1 -s "Subject" email@somewhere.com'

Can't stat email@somewhere.com: No such file or directory
email@somewhere.com: unable to attach file.

email@somewhere.com: unable to attach file.

alias emailattach mutt -a !:1 -s "Subject" email@somewhere.com

echo "Message Body" | emailattach /path/to/attachment

echo "Message Body" | emailattach

Bad ! arg selector.

$ alias emailattach 'echo "Message Body" | mutt -s "Subject" email@somewhere.com -a !:1'