The only supported version is the latest. This should be the latest code with all fixes and what users should see on https://emailthing.app.
Report any discovered vulnerabilities to me (RiskyMH) by emailing security@riskymh.dev. Your report will try to be acknowledged within 5 days. To the greatest extent possible, I will endeavor to keep you informed of the progress being made towards a fix and full announcement, and may ask for additional information or guidance surrounding the reported issue.
Note: As EmailThing earns nothing, I won't be able to give much but I would appreciate you reporting responsibility!