Avast Premier Blocking Exchange Emails

Avast Free Antivirus / Premium Security
1

Hey all,

Just installed Avast on a domain joined Windows 10 Enterprise x64 device but I’ve been unable to connect to Exchange in Outlook 2016 on a domain network after installing Avast Premier. I suspect it’s to do with the man in the middle SSL cert. method Avast uses to scan SSL traffic.

I have tried the following:

  • Modified Outlook.exe process to allow allow all ports, all IPs and all protocols to have in/out.
  • In Web Shield I added both the internal and external exchange webmail IPs to the exclusions
  • Disabled SSL scanning
  • In Mail Shield I disabled Scan inbound mail, outbound mail.
  • Disabled Mail Shield
  • Uninstalled Spam filter
  • Temporarily disabled all components
  • Tried on Wi-Fi and Ethernet
  • Removed Avast certificates but they get re-added on reboot.

It works when I connect to webmail outside my corporate network, only fails inside.

None of the above fixed the issue, the only way to fix the issue was to uninstall Avast.

Cheers,
Hynesy

2

https://forum.avast.com/index.php?board=77.0

3

Thanks but I’m not referring to Avast Business, we use Sophos in our corporate environment but I find Avast much better so I installed an extra copy of Avast Premier on my work machine instead.

Cheers,
David

4

Do you have avast and Sophos installed?

5

Nope, got rid of Sophos. (Y)

6

Ask the admin what settings are required to connect and set them in avast.

7

Hi hynesy,
if you disable only avast outlook plugin (options->addins; restart outlook) does it help?

Thanks,
pm