Hi @Jan Vojtěch Vaníček ,
Welcome to our forum!
Agree with DillonJS.
As a supplement, Gmail has announced that "To help keep your account secure, from May 30, 2022, Google no longer supports the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password". Affected by this, we need to using Outlook 2019 or newer, Office 365.
Hope the above help!
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