What is your anti-virus software?

Anti-Virus are Avast. But in time start by Thunderbird are "normal" / ca. 40 seconds for start thunderbird by 4 Mail-Accounts.

<blockquote> But in time start by Thunderbird are "normal" / ca. 40 seconds for start thunderbird by 4 Mail-Accounts. </blockquote> I don't understand why you're trying to say. Since you marked your topic as 'Solved', are you saying your problem has been fixed? If so, how? Avast has always been problematic in connection with Thunderbird - see https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues#AVAST Also, these are some generic suggestions to avoid problems with anti-virus software. Create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data#w_how-to-find-your-profile Don't let your anti-virus software scan incoming and outgoing messages. Don't let your anti-virus software scan attachments. Don't let your anti-virus software intercept your secure connection to the server. Remove any add-ons your anti-virus software may have installed in Thunderbird. Keep it working. https://kb.mozillazine.org/Keep_it_working_-_Thunderbird And last but not least, backup your Thunderbird profile on a regular basis. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile