What open source solution is suitable for a corporate mail server?

Question

linux

Good afternoon.
Please share your practice.
What is the best Open Source mail server on Linux to use for the corporate segment?
It is desirable that there would be a Web GUI, the ability to integrate with AD.
The number of users is just over 100.
Thank you, thank you in advance for your answers.

Answer 1

(postfix or exim) + dovecot
Integration with AD - using LDAP authorization.
Almost any web muzzle is screwed on, they are in stock.

Answer 2

As an almost ready-made solution - Zimbra

Answer 3

The most wonderful thing I've met so far is Zentyal . Essentially ubuntu + ebox.
Simple, reliable.
Everything you need for self-hosting in the office is there. this is AD, and mail, and antivirus (the simplest, but there is one), and a decent firewall, and openvpn in a box ... in general, I use it myself, and I recommend it to you.
previously they called it free as the Community Edition... but, commercialization is a delicate matter, and they renamed it the Development Edition.
Tried (long ago) ClearOS. Also all in the box, but based on rhel. and that version, apparently clearos 5, did not like it.

Answer 4

RoundCube / Horde / eGroupWare