UTM 9 WAF Outlook Anywhere login failed

Hi there,

 

I’ve configured WAF for an Exchange Server 2019 according to this guide:

https://www.frankysweb.de/sophos-utm-9-4-waf-und-exchange-2016-ohne-rpcoverhttp/

 

OWA and ActiveSync works fine but I have trouble getting Outlook Anywhere working.

Outlook shows a login prompt for username and password and reject the login.

 

Everything works when WAF is disabled and a HTTPS DNAT rule is setup. No errors are shown in Microsoft Remote Connectivity Analyzer.

 

If DNAT is disabled and WAF is setup, the login with Outlook Anywhere does not work. Even changing the firewall profile from reject to monitor doesn’t do anything.

Microsoft Remote Connectivity Analyzer shows an error accessing MAPI Endpoint HttpStatusCode: 401.

WAF log says:

2024:05:29-13:54:46 login httpd: id="0299" srcip="xxx.xxx.xxx.xxx" localip="192.168.xxx.xxx" size="0" user="-" host="xxx.xxx.xxx.xxx." method="POST" statuscode="401" reason="-" extra="-" exceptions="SkipURLHardening" time="8639" url="/mapi/emsmdb/" server="exchange.domain.de" port="443" query="?MailboxId=ae0ba1c8-xxxx-xxxx-xxxx-24ad5118c4fd@domain.de" referer="-" cookie="-" set-cookie="-" websocket_scheme="-" websocket_protocol="-" websocket_key="-" websocket_version="-" uid="ZlcXhiMERRXTxxxxxqNgAAACk"

 

Can anyone help?