How to set up mail for a domain on Yandex if the site is on AWS?

Question

Domain Name System

I have had a domain name registered on namecheap for a long time. Yandex has a "mail for domain" service that I use. Everything is very conveniently configured and there are no problems with the mail.
Recently there was a need to create a one-page html site (essentially with contact information). The choice of hosting provider fell on Amazon (free). Thus, it turns out that the site will be located in S3, the domain name will be administered on namecheap, mail will work on the Yandex infrastructure.
I managed to create a website, it is available at the Amazon link. As I understand it, in order to bind my domain name to the site, I need to register the received Amazon DNS in the domain control panel in namecheap. This is understandable, but several questions arise.
How to connect my domain (it should work in fact, after specifying Amazonian DNS in the namecheap control panel) from Route 53 with a site in S3?
How to set up the work of mail with mail for a domain from Yandex? Indeed, in fact, all the settings associated with the domain (including mail) will now be located in Route 53, and there is no possibility to work with mail
Thank you

Answer 1

You configure NS to address Route53, and there you already specify MX records. Route53 is just a DNS service, nothing more. To set up mail, you only need MX records at a minimum and that's it

Answer 2

In the dns, you just need to register their record, what's the difference where the site is hosted, it may not even exist, the mail does not care about it