With this script I can record a message from the command line and send it to a recipient.
arecord -D hw:1,0 -f cd -c 1 -t wav voicemail.wav
oggenc -q 6 voicemail.wav
echo "" | mutt -s "Your subject" -a voicemail.ogg -- firstname.lastname@example.org
For determining the microphone used by arecord, this was very useful.