What would you recommend for email collaboration in a small company?

Question

CRM

There is a small, not rich, but very dynamic company in which people use emails very actively.
The main emphasis in the workflow is not on personal mailboxes such as first name.surname, but on subject ones like sales, info, support, etc.
Now every employee who is somehow concerned with the topic of a particular mailbox stupidly pulls out all the mail for himself through POP3.
At the same time, there is not enough opportunity for everyone to see the entire history of correspondence, attach a comment to the letter (for employees, not for the addressee), put a mark so that everyone can see the status of this correspondence and so that several people do not react to the same thing.
The first thing that comes to mind is Exchange, but this solution is too cumbersome in many plans.
Another option is corporate GMail.
The third - some of this (at least show what has already been read), as far as I remember, regular IMAP can do.
Advise any sufficiently functional and at the same time quite lightweight solution. Or something that can be raised on a shared hosting, or on your own Linux server, or something inexpensive from SAAS.
What is needed is convenient functional collective work with mail, without unnecessary CRM / groupware-bells and whistles, dictating their work methodology and imposing their own restrictions.

Answer 1

GMail is a great solution.

Answer 2

Everyone wants a highly functional yet simple solution
So far only answers this exchange so4net.com/index.php/ru/blog/102-base-rulls-of-email
I can advise exim4 or mail Kerio

Answer 3

Corporate Yandex mail + IMAP
In general, get away from solving internal issues by email, use services like Asana - significantly reduce the time for making decisions and tracking processes

Answer 4

Zimbra Collaboration - there is also an open source version.
Can, for example, a chain of letters that Kerio can't. There are also things like a briefcase for storing data, with the ability to mount a briefcase, like an OS disk, calendars, tasks, etc. In general, a bunch of bells and whistles for all occasions.
It is demanding on hardware, but everything is configured quite flexibly.