What are the SMTP configurations you'd like to see?

Mattermost team here,

We want to make it easier to [set up SMTP email for Mattermost][1]. We’d like to ask help from the community to:

  1. Let us know what popular SMTP service you’re most likely to use (we document AWS SNS, what else would you like to see?)
  2. Please share links to any SMTP install instructions you feel we could add to the instructions (Office365, OpenSMTP, Mandrill, etc.?)

Any thoughts?
[1]: https://github.com/mattermost/platform/blob/master/doc/install/SMTP-Email-Setup.md
[2]: https://github.com/mattermost/platform/blob/master/doc/install/SMTP-Email-Setup.md#how-to-enable-email

In the Gitlab Omnibus install, will you just hook into Gitlab’s mailer (or mailer setup)?