@Berny Ik log nu in en zie ik uw oplossing. Inmiddels had ik al Technisch support geraadpleegd. Hierbij stuur ik je hun antwoord en de (succesvolle) uitwerking. Ik heb wel do not scan all traffic aangeklikt, maar dat verder niet gespecificeerd. Nogmaals bedankt voor uw tijd en interesse. Met vriendelijke groet, Felix Huijs Op 14-4-2020 om 12:14 schreef Kaspersky Lab Support: Please proceed as follows: > > 1. If the main window of Kaspersky application is not on your desktop, bring it up by double-clicking the Kaspersky desktop shortcut (icon) or by double clicking on the Kaspersky icon in the bottom right corner of the screen; > 2. Click on the Gear icon in the bottom left corner of the Kaspersky window; > 3. On the left side menu select 'Additional'; > 4. On the right side menu select 'Threats and Exclusions'; > 5. Under 'Exclusions' click on 'Specify trusted applications'; > 6. Click 'Add'; > 7. Pick "Thunderbird" from the list or click 'Browse' in the bottom left corner to manually locate the Thunderbird executable (.exe file) and click "Next". > 8. Check "Do not scan all traffic" box. > 9. Click on "Add" -> close Kaspersky "Settings" -> restart your PC and check if the issue persists. Mijn antwoord: I proceeded as you ordered, I picked "Thunderbird" from the list. After restarting the computer, opening TB and start downloading e-mail, a dialogue window opened, saying You are about to overwrite how TB this website defines" "Location 127.0.0.1;(port #)". Clicking the button Show certificate, the new Spamihilator certificate is showed. In the dialogue window I confirmed this exclusion. After restarting the computer, permission was granted without any extra action.