Collaboration with one mailbox?

Question

Mail server

We have one shared external mailbox, [email protected]
It is configured for all managers via POP ( the size of the box is small, once a week all mail is deleted from the server and remains only with managers on machines ).
The mail program Thunderbird is used .
Now the question arose of how to mark mail so that these marks are available and visible to all managers.

Answer 1

Raise your server with IMAP, picking up mail from this little one.
And let managers work with IMAP.
Well, or not your own, but through the same buzz or Yandex, organize a collection.

Answer 2

Register your domain on Gmail, Mail.ru, Yandex - and connect to it via IMAP, as Dvvarreyn
advises Or via the VEB interface. All correspondence will be available always and from any place. Any notes will be displayed for everyone at once.
Zhmail seems to have become paid, Mail.ru and Yandex are free.