[firestore-send-email] Support for Open/Click Tracking

[tsgregoryv]

[REQUIRED] Extension name

firestore-send-email

What feature would you like to see?

I would like to see support for open/click tracking with bulk email service providers like SendGrid. SendGrid has the option to add a link to an event webhook. It would be nice to have a cloud function available to receive email provider events. The cloud function would then update the firestore document used to trigger the email send with event data (such as clicks/opens).

How would you use it?

Event data would be displayed to end-users to provide more detailed email interaction information.

[cabljac]

Thanks! added to under consideration.

[huangjeff5]

Interesting, since this is relating to SendGrid as well, I would recommend posting the request here as well: https://github.com/twilio-labs/twilio-firebase-extensions/issues

This may incentivize them to build out a SendGrid version of this extension :)

[tsgregoryv]

A good idea. I was concerned this might be too 3rd party specific. I decided to post the request there too: https://github.com/twilio-labs/twilio-firebase-extensions/issues/43