Step Wise Manual Onet mail settings for thunderbird
If you don't have a Onet mail address. you can create an email id from here then you can Onet email login.
Open Thunderbird Software App. Click on Email
When you click on the email, pop-up Set UP an Existing Account Screen.
Enter Your name, Onet Email address and Password then press Continue.
Click on the Manual config menu at bottom.
Enter Below Onet incoming server settings.
In incoming click on the dropdown menu and select IMAP.
Add server host :imap.poczta.onet.pl
Port: 993
select SSL/TLS
Enter Below Onet outgoing server settings.
In outgoing select SMTP.
Add server host :smtp.poczta.onet.pl
Port: 465
select SSL/TLS
Tap on Done. Now you are ready to use your Onet email account on your Thunderbird.