Step Wise Manual Corp mail settings for thunderbird
If you don't have a Corp mail address. you can create an email id from here then you can Corp 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, Corp Email address and Password then press Continue.
Click on the Manual config menu at bottom.
Enter Below Corp incoming server settings.
In incoming click on the dropdown menu and select IMAP.
Add server host :imap.mail.ru
Port: 993
select SSL/TLS
Enter Below Corp outgoing server settings.
In outgoing select SMTP.
Add server host :smtp.mail.ru
Port: 587
select SSL/TLS
Tap on Done. Now you are ready to use your Corp email account on your Thunderbird.