Add persistance

[IngusSkaistkalns]

Added db persistance with available cmd line option db-path for db file.
Added questionable UI message handling before quiting mailcatcher for consistency, because for file db we wont lose our messages.

[sj26]

I kinda have a rewrite in the wings that I was planning to implement this with... I do like the approach but stay tuned.

[neoice]

would supporting alternate database backends be one method of implementing persistence?

I'm currently using MailCatcher in "single user development environments": low activity, nightly database resets, regular daemon restarts. I'd like to deploy MailCatcher to our "integration environment", but the activity level there is much much higher. I don't want to restart MailCatcher every day so the in-memory SQLite DB doesn't balloon to an insane size. having MailCatcher write to MySQL solves persistence and long-term memory usage.

[andrhamm]

Would love to see persistence make it into master 👍

[ghuntley]

+1 SQLite to disk would suffice w/configuration option to expire after x days or y messages.

[fdrouet]

👍

[andreyev]

👍

[ukazap]

When can we expect to see this on master?

[sj26]

It's a dream, and there are lots of unanswered question, so no time frame.

If you'd like persistence, maybe try: https://github.com/mailhog/MailHog