Windows 10? Updating from which version? To which version? (Please always state your version)

Hello My version of Windows 10 is 22H2 last update KB 5072653 Best regards Alain Peri

Try to improve performance by checking the following:

Anti-Virus: Do you have Anti-Virus scanning Thunderbird folders on startup or/and scanning emails as they are downloading? Anti-Virus may the default installed or one you installed. If yes: I suggest you create an exception not to scan your Thunderbird profile folder.

If you downloaded Thunderbird from the official website :

• https://www.thunderbird.net/en-US/thunderbird/all/

This is the Thunderbird profile folder to not allow scan C://Users/username/Appdata/Roaming/'Thunderbird

Firewall: Controlled by computer default or by an Anti-Virus product. Access Firewall and make sure the Thunderbird program is set up as an allowed program.