Support for Mailgun

[Nowaker]

Mailgun offers 10,000 free emails a month. Sendgrid doesn't have a free plan at all.

[mzrzvi]

@Nowaker I think it was free when I wrote this. I'll switch to Mailgun soon

[Nowaker]

I'd propose to add support for Mailgun. Like, use Sendgrid when SENDGRID_API_KEY, and use Mailgun when MAILGUN_API_KEY is passed.

[mzrzvi]

Makes sense -- maybe have a config env var for either

[mzrzvi]

@Nowaker Would you be interested in making a pull request?

[Nowaker]

@mzrzvi Not really. If I had to jump into the code, I'd probably redo this as ruby-slack-to-email. :-)

[Nowaker]

Or rather than deal with any services, would do it as an AWS Lambda thing and provision with Terraform. https://medium.com/@pixelcodeuk/create-a-slack-slash-command-with-aws-lambda-83fb172f9a74