I have a machine A with W7 and a machine B with W10. In both install last TB 52.1.1. In W7 I can install the email accounts without any problem, following the automatic process that facilitates TB. In W10 I try and in the DB ISP of Mozilla does not find the domain. Then try with the most typical server names and also not get it. Manually, it does not connect either. I have discovered that: - I installed TB 38.0 on W10 and can create the accounts and send-receive emails. - I update to TB 38.5 and I can also create the accounts and send-receive emails. - I update to TB 45.8 and the created accounts no longer connect and I can not create new accounts. In W7, in the manual configuration for IMAP I can choose Oauth2 authentication, but in W10 this option does not appear. And I'm installing the same version of TB. Thunderbird not good in W10 ??? Regards, Isidre