I forgot my password
If you forgot your Yandex password, try resetting it manually. To do this, follow the instructions on the Restoring access page.
If you linked a phone number or email address to your account, enter them to receive a confirmation code. If you get a message that your email address or phone number is incorrect, make sure you didn't make any mistakes when entering them. If you entered them correctly, try to remember any other phone numbers or emails that you might have linked to your account.
If you didn't link an email address or phone number to your account, then you will have to answer a security question to restore access. If you don't answer the question correctly the first time, try an alternate spelling or change the keyboard language.
I do not remember my Mail for domain password
If your email address ends with any domain other than ya.ru, yandex.ru, yandex.by, yandex.com, yandex.com.tr, yandex.kz, or yandex.uz, it means your account was created using Yandex.Mail for Domain. By default you can restore access as usual by receiving a confirmation code or by answering a security question.
But the domain administrator can prevent users from changing their passwords. In this case, Yandex cannot help you restore access; only the administrator can change or remind you of your password. Most likely, you can contact the administrator via the website where you registered the mailbox.