What are the different Message Status that ITextHub offers, and what does OTHERS means? 

Following are the status defined in IText Hub

DELIVRD
UNDELIV
REJECTD
FAILED
Failed
EXPIRED
ACCEPTD
DELETED
UNKNOWN
OTHERS
SUBMITTED

Others Count consist of => FAILED + Failed + DROPPED + OTHERS + EXPIRED + ACCEPTD + DELETED + UNKNOWN + DND