I wanted to know if apostile is mandatory for Indian passport holders residing at Boston if you are planning to get attestation done at NY embassy by mailing all documents?
If yes, then can apostile be done by mail after notarizing all 3 signatures in the state of Massachusetts?
Yes, every state that comes under NY Indian Embassy jurisdiction will need APOSTILE if sending documents by postal mail.
See here for direct NY embassy link: https://www.indiacgny.org/pages.php?id=1060