### Stable endpoints
/$LISTNAME/m/$MESSAGE_ID.html -> HTML content (short quotes)
/$LISTNAME/m/$MESSAGE_ID.txt -> raw original
/$LISTNAME/m/$MESSAGE_ID -> 301 to .html version
/$LISTNAME/f/$MESSAGE_ID.html -> HTML content (full quotes)
/$LISTNAME/f/$MESSAGE_ID -> 301 to .html version
### Stable endpoints
/$LISTNAME/m/$MESSAGE_ID.html -> HTML content (short quotes)
/$LISTNAME/m/$MESSAGE_ID.txt -> raw original
/$LISTNAME/m/$MESSAGE_ID -> 301 to .html version
/$LISTNAME/f/$MESSAGE_ID.html -> HTML content (full quotes)
/$LISTNAME/f/$MESSAGE_ID -> 301 to .html version