What programs do you recommend for registering incoming/outgoing correspondence?

Question

Document flow

I want to transfer office managers from the 18th century to the 21st :)
Now they write down all correspondence in a big grandmother's notebook, where it is very difficult to find something later.
It is desirable freeware or with the ability to bypass this matter)
Thank you :)

Answer 1

Look at MicroDoc-3 - a network program for electronic document management. Everything you need is there, nothing more.
While in beta - free, after the price the author promises to make about 5 thousand rubles.