Can Google App Engine use a third party SMTP serve

Question

Google App Engine currently limits you to 2,000 emails per day (for free) via their API.

I am trying to find a definitive answer if it is possible to use a third-party system if you need to send more. I know that they disallow raw sockets, so I would assume that there might be trouble with this approach... but surely I'm not the first to see it.

Worst case, I can build a simple offsite web service that my GAE can call... but I'd much rather just be able to send directly through an SMTP server.

Thanks!

Answer 1

I've successfully used third party providers for email services with Google App Engine. I've used both SendGrid and MailGun using their HTTP-API.

Answer 2

We use the Postmark mail outsourcing service via the hutools.postmark API. Since the communication is HTTP based, it works like a charm on Google AppEngine. This might be an option for you, although it is also a for-pay service. We use it to get arround GAEs sender restrictions.

Answer 3

Nope.

You're correct: you cannot make raw socket requests, nor any other direct outbound requests except through the urlfetch API. To talk to an external SMTP server, you would need to use a webservice as a proxy.