https://www.reddit.com/r/lifehacks/comments/7mplo0/send_a_text_from_your_computer_via_email/
more - https://kb.sandisk.com/app/answers/detail/a_id/17056/~/list-of-mobile-carrier-gateway-addresses
mobile lookup :
https://www.twilio.com/lookup
https://www.freecarrierlookup.com/
more - https://kb.sandisk.com/app/answers/detail/a_id/17056/~/list-of-mobile-carrier-gateway-addresses
mobile lookup :
https://www.twilio.com/lookup
https://www.freecarrierlookup.com/