getAddress v : Returns the address of selected email in the RFC-5322-compliant message ID format

getFrom v : Returns the sender of selected email in the format name, address

getSubject v : Returns the subject of selected email

getPreview v : Returns the preview of selected email

getBody v : Returns the body text of selected email

Or use the Javascript equivalents, getaddress method etc.

Example:

tell application "FMail2"
  getFrom
end tell

would return the sender information of the selected email.