How to secure work mail and Yandex disk for 5-6 users?

Question

Email

Good morning everyone.
Problem: there is a legal company with friends (IPshka for 6 people of the state), where each of the 6 people uses 1 common mail + one common cloud with important documents (Yandex Disk).

Question: How to secure this solution? Mail has already been broken 2 times (according to a friend (owner) of the mail). Maybe there is a conditional middleware software that is a layer between mail (or a cloud) and allows you to bind n-number of mobile phones for two-factor authentication? The problem is that only one phone can be linked to the mail for two-factor authentication, and the same thing on the cloud.

As I see it: 6 people use 1 mail and one cloud. For authentication, they go to some service that generates an SMS, or anything that allows you to safely use mail or the cloud.

If someone had experience with solving such a problem, I will be glad if you share your experience.

Answer 1

To begin with, the very idea of ​​sharing one account is extremely harmful from a security point of view. Everything is conceptually wrong. And, of course, using such a service for some important things is also a bad idea.
Your idea won't work. You cannot change the behavior of the service.

Answer 2

one common cloud with important documents (Yandex Disk)

You don't have to continue further, the key word is Yandex... Until then, you can forget about security and privacy a priori. If you need to do well, use your server with NextCloud for example

Answer 3

If with mail, then you can do 6 mail and from the main one send everything to them
. The disk can be shared with folders
. As they said above
, NextCloud is an excellent solution. Yandex has passwords for separate services
. They also have a two-factor application for authorization on their service.