Hello leo leo ,

Thank you for reaching out to the community, in that case you can always create an exception for the exchange auto discover.

i already done but it still blocked have you  a screen shot for this exception how and are the skipped rules in the exception standard id in all sophos version ?

You can create an exception with the reference below:

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But if the request are still blocking, then it could be casue of the server and it may not be firewall related at all !
As in a debug request can be analyzed with the reference below:

1672657444.718117086 [12992/0x7f0e21565800] fwid=4 fwflag="" iap=13 aap=0 conn_id=1893385491 id="0002" name="web request blocked" action="error" method="CONNECT" srcip="10.X.X.X" dstip="38.96.29.10" user="Goku" statuscode=500 cached=0 trxlen=517 rxlen=0 url="autodiscover.contoso.com/" referer="" type="" upload_file_name="" upload_file_type="" download_file_name="" download_file_type="" authtime=0 dnstime=6 cattime=279 avscantime=0 fullreqtime=15084713 ua="" activity="" av_transaction_id="" categoryname="Information Technology" category="29" app_id=0 app_name="None" app_cat="None" exceptions=""
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The HTTP status code 500 is a generic error response. It means that the server encountered an unexpected condition that prevented it from fulfilling the request. This error is usually returned by the server when no other error code is suitable.
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For the reference refer the following links:
1.) Autodiscover service in Exchange Server
2.) Autodiscover for Exchange

You can create an exception with the reference below:

====================================
But if the request are still blocking, then it could be casue of the server and it may not be firewall related at all !
As in a debug request can be analyzed with the reference below:

1672657444.718117086 [12992/0x7f0e21565800] fwid=4 fwflag="" iap=13 aap=0 conn_id=1893385491 id="0002" name="web request blocked" action="error" method="CONNECT" srcip="10.X.X.X" dstip="38.96.29.10" user="Goku" statuscode=500 cached=0 trxlen=517 rxlen=0 url="autodiscover.contoso.com/" referer="" type="" upload_file_name="" upload_file_type="" download_file_name="" download_file_type="" authtime=0 dnstime=6 cattime=279 avscantime=0 fullreqtime=15084713 ua="" activity="" av_transaction_id="" categoryname="Information Technology" category="29" app_id=0 app_name="None" app_cat="None" exceptions=""
=====================================
The HTTP status code 500 is a generic error response. It means that the server encountered an unexpected condition that prevented it from fulfilling the request. This error is usually returned by the server when no other error code is suitable.
=====================================
For the reference refer the following links:
1.) Autodiscover service in Exchange Server
2.) Autodiscover for Exchange

Thank you for support but the firewall keep blocking the auto discover link. have you please another advice?

I would suggest you to diagnose with the debug logs to narrow down situation, it is not a hardware fault ! 

Request blocked

The web application firewall has blocked access to /Autodiscover/Autodiscover.xml for the following reason:

No signature found


still blocked from outside

internally it works

In that case WAF troubleshooting can help, check the reverproxy.log while accessing the site from outside !

The reason here is Static URL Hardening, no signature found. 

The reason why activating both functions solves those issues is that in case either form hardening or URL hardening find that a request is valid, the WAF accepts the request.

thank you for answering but am sorry when i say that

but i didn't understand what you talk about
could you please lead me or send me a link which content the basic info

So, under on Sophos Firewall Web-admin > PROTECT > Web server > Protection policies > Exchange AutoDiscover > Open

And refer the following guide !
Add a web server protection (WAF) rule - https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/WebServerProtection/WAF/Rules/WAFRuleAdd/index.html

Many thanks i have found the problem and solved it.