Missiva, carta.
n.Specially sent; intended or prepared to be sent; as, a letter missive.
Missile.
That which is sent; a writing containing a message.
One who is sent; a messenger
letter, text generic term, textual matter generic term, document generic term
Vogais: iie
Consoantes: mssv
massive, misgive, misgave, mischief, misshape, misbehave, massif, miskeep, mississippi, mince pie.