This is a thing to assist with using text messages and phone calls from your computer. It is intended sortof as a Google Voice replacement. It doesn't store messages anywhere but routes them through email.

You can pick some combination of these services to use:

• Twilio: incoming calls and texts
• CallWithUs: outgoing calls and texts
• Plivo: outgoing calls; incoming and outgoing texts

• SMS ↔ email
• Voice ↔ SIP
• Voicemail → email

• Get text messages by email (including MMS attachments if using Twilio).
• Send text messages using email.
• Get voicemail recordings by email (currently implemented only with Plivo).

Handling incoming calls and texts can be set up using Twilio or Plivo. Twilio is more popular, gives out promotional credits more often, and has more features. Plivo is cheaper and open source.

• Copy twilio/config.example.php to twilio/config.php. Replace the addresses in the config file with your addresses.

• On Twilio, set the request URLs for your phone number to point to the voice and text scripts, e.g.:

  • Voice: https://example.org/sip/twilio/voice.php
  • Messaging: https://example.org/sip/twilio/text.php

• Copy plivo/config.example.php to plivo/config.php. Replace the addresses in the config file with your addresses.

• In the plivo directory, create a file, voicemail.mp3, with the recording that you want callers to hear as a voicemail prompt.

• In Plivo, create an application. Call it something like "Forward to Email". Set the URLs to point to your text and voice scripts, e.g.:

  • Answer URL: https://example.org/sip/plivo/voice.php
  • Message URL: https://example.org/sip/plivo/text.php

• Set your phone number's application to be the application you just created.

This section sets up your mail server so that you can send mail to addresses like [email protected] and have them be delivered as text messages.

To use CallWithUs instead of Plivo for outgoing texts, follow these steps using cwu instead of plivo.

• Copy plivo/config.example.sh to plivo/config.sh. Replace the API key with yours, from your Account Info page.

• In /etc/postfix/main.cf, add alias_maps = pcre:/etc/postfix/aliases.

• In /etc/postfix/aliases, add /\.sms@/ root

• Run postmap /etc/postfix/aliases

• In /etc/postfix/main.cf, in the item smtpd_recipient_restrictions, add to the end of the list (somewhere after permit_sasl_authenticated and permit_mynetworks): check_recipient_access pcre:/etc/postfix/recipient_access

• In /etc/postfix/recipient_access, add a line /.sms@/ REJECT. This is to prevent unauthorized people from using your server's sms service.

• In /etc/postfix/transports, add two lines. First /sms/ sms. Then /./ followed by what you had in mailbox_transport previously. e.g. if you are using Dovecot for mail delivery, you may add something like /./ lmtp:unix:private/dovecot-lmtp.

• In /etc/postfix/master.cf, add two lines:

sms  unix  -       n       n       -       -       pipe
  user=cel argv=/path/to/this/repo/plivo/send-text.sh ${recipient}

This defines the sms transport used the previous step.

• Run postfix reload

Note that terminating a PSTN call to a SIP address with Plivo or Twilio counts as both an incoming call and SIP call. I think this is true for outbound SIP → PSTN calls as well, which would be counted as both outgoing calls and SIP calls.

• Twilio: record and send voicemails
• Twilio: delete resources after sent/received
• Twilio, Plivo: Consider making and sending voicemail transcriptions
• Make it a web app (just kidding)
• Make email messages thread properly