We’ve successfully added configurable outbound SMTP retention period (defaulting to 0 days). We have deployed this to production as well. Screenshot and commit reference below. We’ve also updated our Privacy Policy at https://forwardemail.net/privacy#information-collected to explain this further.
Screenshot:
Commit:
https://github.com/forwardemail/forwardemail.net/commit/1f732fb96c06231f8e11cc6b4d3d6486d2346d32
Summary:
Now outbound SMTP emails are immediately purged/redacted of message body content (we still retain headers for 30 days for spam/abuse prevention).
@jonah @Niek-de-Wilde @dngray @freddy @olivia Are there any blockers preventing us from being included? I think we’ve proven that we are stable, reliable, privacy-focused, security-focused, and extremely transparent. We also have met and exceeded all existing criteria for inclusion (as documented above in this thread). And we’re still the only provider that is truly 100% open-source and transparent in every way 
We submitted a PR already so it’d be rather easy to review and merge at https://github.com/privacyguides/privacyguides.org/pull/2358. Happy to make any changes requested as well, just make a comment on that PR or related commits.
As of today there are over 431,549 domains using our service including organizations such as Netflix, Disney Ad Sales, The Government of South Australia, The Government of Dominican Republic, The University of Maryland, The University of Washington, and many more.
We’re only getting better too! We plan to launch support for CalDAV (calendar), CardDAV (contacts), dedicated IP address add-ons, and newsletter support → all hopefully by early this year (2024)!