Thanks to https://github.com/cldfzn for the workaround for emails using mailcatcher:
More than likely your isp is blocking your email attempts or you’re being spf filtered. I set up a mailcatcher docker container (https://quay.io/repository/cldfzn/mailcatcher).
- Set up the mailcatcher: docker run -d --name mail -p 1080:1080 quay.io/cldfzn/mailcatcher
- Start the mattermost docker container linking mailcatcher: docker run -d --name mattermost -p 8065:80 --link mail:mail mattermost/platform:helium
- Change the config_docker.json EmailSettings to “mail:25” instead of “localhost:25” and restart the docker container (or you can modify the Dockerfile and rebuild)
- Use the sign up now option (you’ll have to alias www.yourserver to the ip of your server)
- Check yourserver:1080 once the email has been sent and you should see it in there
- You’ll need to alias teamname.yourserver to get to your team page login once you’re done setting up
Basically you just need to intercept the mail going out in some manner. I just happened to have a mailcatcher from another project.