Will the mailboxes with the content in the mail on the domain on Yandex be saved when changing the DNS?

Question

Yandex

So, colleagues, actually a subject. It is necessary to transfer the site between hosters with the change of ns and, of course, adjacent records. MX record, of course, will be affixed.
At the moment, the mail is on the mail for the Yandex domain, and now on the connection. In the account on the connection, of course, no manipulations are provided.
There are a lot of mail, for many years, for its loss they wheel at least :)
I know that the question is rather stupid, and I suspect the correct answer, but I want to make sure.
I know how to use Google, I came here purposefully :)

Answer 1

MX is not related to mail storage at all.
But if the record disappears for a while, you will lose NEW letters. They won't be able to reach.
Nothing will happen to the old ones.