I am trying to migrate an yandex mail account to zoho mail account. I am confused with all the related articles/informations in the net. Could someone please outline the process to do it, just thinking about me as a novice with limited knowledge or experience.

A couple of questions from the knowledge gained.
1. I believe we have to delete the yandex current MX from the website records and add Zoho MX. What happens to the emails as we remove the mail exchange record. Yandex stops updating emails and Zoho starts getting emails is it? IS there a risk involved in messing up both sides?

2. What is the mode of migration suggested. Yandex doesnt give any option of migration on ts web mail so eml format is impossible. Outlook configured, we can get a pst. Should we use this pst for all mail migrations then? or there is a better way of doing things.

3. We cant afford any disruption or stoppage and how do we do it? WHat are the best ways?