This Docker image will listen on port 25, and do nothing else than responding to SMTP
traffic in a valid way, and piping incoming emails to stdout.
See https://github.com/koyaan/mailtrap for a fork which generates a TLS certificate and securely listens on port 435 instead.
docker pull michielbdejong/mailtrap docker run -p 25:25 --name mailtrap michielbdejong/mailtrap docker logs -f mailtrap
Use case: getting a startssl cert
If you want to get a StartSSL cert for a domain you just registered, do the following:
- run this mailtrap on a server
- set the MX record to e.g. mail.domain.com. (priority e.g. 10)
- add an A record for mail to the IP address of the server where you are running the mailtrap
- In the domain validation wizard, pick any email address (e.g. firstname.lastname@example.org)
- Check the docker logs and copy-and-paste the validation token from it