Bitte lesen: https://www.betterbird.eu/support/ (unten):
Sometimes virus scanners raise an alert for the Betterbird installer or the installed executable. If you've downloaded the installer from our website, these are false alarms. You can submit alleged malicious code to a recognised online virus scanner like VirusTotal or Jotti. We are self-signing all executables, you can download our certificate which you need to install into "Trusted Root Certification Authorities" (check with certmgr.msc). The result looks like this. For our own use, we've excluded the Betterbird program directory and process from further scans.
