Consider replacing Mailcatcher with Mailhog

[aaemnnosttv]

Mailhog is a newer project inspired by Mailcatcher, written in Go.

Apart from it's more pleasing aesthetic appearance, I believe it offers some features and benefits that Mailcatcher does not.

• native notifications on MacOS (maybe others too?) when inbox is open
• exposes an API for fetching messages programmatically
• can "release" messages to a real SMTP server for delivery
• in memory or persistent message storage
• offers a replacement for sendmail
• easy to install + configure in Docker https://registry.hub.docker.com/u/mailhog/mailhog/

It may also be worth noting that Flywheel's Docker-based "Local" development environment switched from Mailcatcher to Mailhog as part of its 2.0 release.

From https://github.com/10up/wp-local-docker/issues/132

[jeffpaul]

@aaemnnosttv note that I'm putting this into the Future Release milestone for now given that we've got Mailcatcher working. I do agree that replacing it with Mailhog would be nice, but we're likely to tackle some other needs before this. If you manage to have time to work on a PR for this, then we'd gladly welcome that in a nearer term release!