Is there a cloud mail client?

Question

Android

Hello.
There was a need for a suitable email client, based on my requirements, most likely it should be some kind of cloud service. Briefly describe my main requirements:

1. the client must run from Win7, Android and preferably WinXP;
2. if the message was read from one device, then it should not be displayed as read on another, but should be loaded;
3. the ability to have several mailboxes of different mailers (@mail.ru, @gmail.ru, yandex .ru).
4. it is desirable that it would be enough to enter the passwords of each of the mails only once, so that when you start from another device you don’t have to do this anymore, which means that the service should allow you to create your own account

Oddly enough, I have not come across anything like this yet, thanks in advance for the advice.
---
gmail.com for some reason was buggy hard for me, I'm trying to restore my acc, writes that there is no such thing, I'm trying to make a new one - I already have one, incomprehensible and inconvenient.
I settled on a client for android from mail.ru and connected additional mails in the web interface on computers. As long as everything suits.
Stopped at mail.ru

Answer 1

Discover the IMAP protocol, any mail client you like, or as advised above, any mail with the ability to collect letters from other mailboxes.

Answer 2

gmail

Answer 3

All of these requirements are fully met by the following cloud mail services -
yandex.ru
mail.ru
gmail.com
Well, and a dozen other not so popular ones.

Answer 4

IMAP access protocol and any mail program that supports it on Win 7 or Android