ManualStep-by-step help for every feature.
FAQQuick answers to common questions.
Write to uschristian@roessner.email
Contact
JMapper Mail is developed by Christian Rößner (Rößner Network Solutions). Write to christian@roessner.email in English or German. Please do not send passwords, tokens or private keys.
A good bug report
- Your device and system version, for example “iPhone 16, iOS 27.1” or “MacBook Air, macOS 26.2”.
- The JMapper version from the App Store page or TestFlight.
- What you did, what you expected and what happened instead. A screenshot helps.
- The diagnostic log, if the problem can be reproduced:
- Open Diagnostics & import → Diagnostic Log (Mac: Tools & settings; iPhone and iPad: the gear menu in the sidebar).
- Turn on Record Diagnostic Log and reproduce the problem.
- Choose Prepare Log, then Share Log …, and attach the file to your mail.
What the log contains. Timing, protocol steps and error codes. It contains no message content, no subjects and no credentials. You can delete it in the same place with Delete Log.
Server or account problems
If you cannot sign in or your server is not found, your mail provider is often the right first contact: JMapper needs JMAP and OpenID Connect with Dynamic Client Registration and PKCE. The troubleshooting section of the manual explains the most common messages.
Security issues
Please report suspected vulnerabilities privately to christian@roessner.email with “JMapper security” in the subject. We will confirm receipt and keep you informed.