I would actually do it with an SMS like this.

  $ cat /bin/awkmail
  #!/bin/gawk -f

  BEGIN { smtp="/inet/tcp/0/smtp.yourISP.com/25";
  ORS="\r\n"; r=ARGV[1]; s=ARGV[2]; sbj=ARGV[3]; # /bin/awkmail to from subj < in

  print "helo " ENVIRON["HOSTNAME"]        |& smtp;  smtp |& getline j; print j
  print "mail from:" s                     |& smtp;  smtp |& getline j; print j
  if(match(r, ","))
  {
   split(r, z, ",")
   for(y in z) { print "rcpt to:" z[y]     |& smtp;  smtp |& getline j; print j 
  }
  }
  else { print "rcpt to:" r                |& smtp;  smtp |& getline j; print j }
  print "data"                             |& smtp;  smtp |& getline j; print j

  print "From: " s                         |& smtp;  ARGV[2] = ""   # not a file
  print "To: " r                           |& smtp;  ARGV[1] = ""   # not a file
  if(length(sbj)) { print "Subject: " sbj  |& smtp;  ARGV[3] = "" } # not a file
  print ""                                 |& smtp

  while(getline > 0) print                 |& smtp

  print "."                                |& smtp;  smtp |& getline j; print j
  print "quit"                             |& smtp;  smtp |& getline j; print j

  close(smtp) } # /inet/protocol/local-port/remote-host/remote-port


  $ echo ricki dont lose that number | awkmail 9998675309@vtext.com me@here.com test

One issue with carrier email-to-sms gateways is that they truncate messages at a relatively short number of characters.

Twilio SMS API, on the other hand, does not have that limit and you can send long SMS messages with a single 'curl' command:

  /usr/local/bin/curl -s -X POST -d "Body=$msg" -d "From=$from" -d "To=$to" "https://api.twilio.com/2010-04-01/Accounts/$accountsid/Messages" -u "$accountsid:$authtoken"

That's simplified - I actually pipeline through 'tidy5' and 'source-highlight' to make the output pleasing:

  /usr/local/bin/curl -s -X POST -d "Body=$msg" -d "From=$from" -d "To=$to" "https://api.twilio.com/2010-04-01/Accounts/$accountsid/Messages" -u "$accountsid:$authtoken" | tidy5 -xml -iq | source-highlight -s xml -f esc | awk 'xor(/TwilioResponse/,/Message/,/To/,/From/,/Body/,/Status/,/ErrorCode/,/ErrorMessage/)' | grep -v "/2010-04-01/Accounts/"