Recommend a gateway for corporate mail and a program for collecting statistics of employees accessing the server!?

Question

Mail server

There are 2 tasks:
1. Mail. Our company pays for hosting corporate mail from a local Internet company, hosting is good, reliable and cheap, but (!) there are absolutely no spam filters. Users for access to mail use the Outlook program from the MS Office suite. In this connection, the question is - is there opensource software for organizing a mail gateway for centralized filtering of mail for spam, as well as checking for viruses?
2. There is a local file server running Windows Server 2012. Active Directory is also raised on it. Interested: with the help of what opensource software it will be possible to organize monitoring of accesses to user data files with logging?

Answer 1

1. https://www.zimbra.com/open-source

Answer 2

1. https://www.hmailserver.com/
2. (There are free and paid, not OpenSource) https://directorymonitor.com

Answer 3

+ to Zimbra, but in general a bunch of links in open source to watch - postfix, sendmail, exim. These are mail servers, but various filters are already attached to them, or filtered by means of the server itself.

Answer 4

And it's even better not to reinvent the wheel and change the client with a spam filter. Or cut it on OutGlitch:
https://technet.microsoft.com/ru-ru/library/cc1791...
https://support.office.com/ru-ru/article/%D0%98%D0.. www.spamfighter.com/SPAMfighter/Lang_RU/Product_In
...
2) www.sevenforums.com/tutorials/123362-audit-log-acc...

Answer 5

I would not advise raising Zimbru for 50 or less users, it is too heavy. Yes, and then grab hemorrhoids during the transfer, the open source version in this regard is slaughtered to the very end.
Install Hmailserver.