Monthly Archives: June 2020

Exchange 2016, Exchange 2019, Mail

Brightmail does not deliver email to Distribution group members

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The Story

Note: This article assumes you have Brightmail Gateway

When you try to send an email to a particular Exchange Distribution group Group@domain.com the result is either users don’t exist or you might get the following error if you test with Microsoft Test connectivity online tool.

Error:

The server returned status code 554 – Transaction failed. The server response was: 5.7.1 Delivery not authorized

Other related errors

‘554 5.7.1: You are not allowed to connect’

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Cause:

Because the group has been cached in the Symantec gateway with its old members, The result could be an error that users don’t exist or delivery is not authorized.

Solution:

To solve this problem, You need to go to Brightmail gateway Administration > Directory Integration and click on your AD Directory > Advanced and hit on Clear Cache.

This would cleared the cached group and take the most recently updated group and its members.

This should resolve the problem.

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How to clear the DDS cache in Messaging Gateway

https://knowledge.broadcom.com/external/article?legacyId=tech132131

Networking, PKI, Security

How to bypass NET::ERR_CERT_INVALID on Chrome

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Locked out of accessing my firewall

After I changed my Antivirus software I used to access a remote firewall publicly on the internet. This firewall has a local selfsigned certificate that no web browser trusts.

Although I added the root certificate to my root store but still none of the browsers would allow me to access it and result in the below error:

Your connection is not private
Attackers might be trying to steal your information from myapp.domain.com (for example, passwords, messages, or credit cards). Learn more
NET::ERR_CERT_INVALID
myapp.domain.com normally uses encryption to protect your information. When Brave tried to connect to myapp.domain.com this time, the website sent back unusual and incorrect credentials. This may happen when an attacker is trying to pretend to be myapp.domain.com, or a Wi-Fi sign-in screen has interrupted the connection. Your information is still secure because Brave stopped the connection before any data was exchanged.

You cannot visit myapp.domain.com right now because the website sent scrambled credentials that Brave cannot process. Network errors and attacks are usually temporary, so this page will probably work later.

On Chrome

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On Firefox

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I searched the web for many work arounds but none of them almost worked including this one which says you can use “Thisisunsafe” or “badidea” on chrome but it did not work.

https://medium.com/@dblazeski/chrome-bypass-net-err-cert-invalid-for-development-daefae43eb12

Using Fiddler

Since I use fiddler to sniff packets and troubleshoot issues on my computer, I remembered that Fiddler has the feature of decrypting traffic (MITM). Fiddler inserts its own root certs and force the traffic to go through it first which makes all the websites trusted even in the case of this error ::ERR_CERT_INVALID

Solution:

So to make this work even temporarily so you can access whatever page you lost access to. All you have to do is:

  • Install Fiddler
  • Let Fiddler Decrypt traffic: To do this go to Tools> Options > HTTPS and select “Capture HTTPS Connects and Decrypt Traffic”
  • Accept and import the root certificates.
  • Click Ok
  • Start Capturing traffic by clicking on the left corner icon image

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  • Now try to browse the page you couldn’t access previously and you’ll get a prompt to accept its certificate. Click Yes if you’re sure of the page and continue.

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Here we go, I got back access to my Pfsense but notice you’ll only be able to access the URL if the capturing is on.

The moment you turn Capturing off the page will not be accessible again.

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Communication, Exchange 2016, Exchange 2019, Skype for Business

Skype for Business IM integration with Exchange 2016 OWA–Part 2

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This article is a completion of Part 1, Click here to go to Part 1

Configuration Steps – Part 2

7. On Exchange: Enable OWA VD Instant Messaging
8. On Exchange: Enable Messaging on OWA Policy
9. On Exchange: Create Enterprise Application for Skype Pool.
10. On Exchange: Create new SettingOverride for Skype for Business.
11- Generate a new Certificate for Exchange IM
12. Assign the newly imported certificate to IIS Exchange Back End site
13. On Exchange: Restart the WebAppPool
14. Log out and sign back in to OWA to Check
15. Troubleshooting methods

    7- On Exchange Server: Enable OWA VD Instant Messaging

    Part of enabling IM integration between Exchange and SfB is to enable OWA Virtual Directory to allow this. The below cmdlet does the job for you on all your Exchange Servers

    From Exchange, Launch Exchange Management and run the following cmdlet

    Get-OwaVirtualDirectory | Set-OwaVirtualDirectory -InstantMessagingEnabled $true -InstantMessagingType Ocs

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    8- On Exchange: Enable Messaging on OWA Policy

    Run the following to enable Messaging for Owa Policy

    Get-OwaMailboxPolicy | Set-OwaMailboxPolicy -InstantMessagingEnabled $true -InstantMessagingType Ocs

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    9- On Exchange: Create Enterprise Application for Skype Pool.

      From Exchange Management shell Run the following cmdlet

      Cd $exscripts

      .\Configure-EnterprisePartnerApplication.ps1 -AuthMetadataUrl “https://sbg-pool01.domain.com/metadata/json/1” -ApplicationType Lync

      The AuthMetadataUrl is going to be your local Skype for Business Pool URL. This URL should work in your Exchange server without any Certificate error. Meaning that the certificate assigned to your Skype for Business pool should already be imported to Exchange Servers to trust this URL.

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        If your previous configuration is correct then you should see the “The Configuration has Succeeded” Message.

          10- On Exchange: Create new SettingOverride for Skype for Business.

          Notes:

          • To configure the same settings on all Exchange 2016 and Exchange 2019 servers in the Active Directory forest, don’t use the Server parameter.

          New-SettingOverride -Name “<UniqueOverrideName>” -Component OwaServer -Section IMSettings -Parameters @(“IMServerName=<Skype server/pool  name>”,”IMCertificateThumbprint=<Certificate Thumbprint>”) -Reason “<DescriptiveReason>” [-Server <ServerName>]

          The Thumbprint you use here will define if whether IM will work or not as this what secures the communication between Exchange and Skype. If you use the wrong certificate your Integration will fail and users wont be able to login to IM through OWA.

          11- Generate a new Certificate for Exchange IM

          IMPORTANT NOTE:

          In order for IM in OWA to work the certificate you will generate must have its common name set as mail.domain.com to match the configuration.

          Using Digicert tool on Exchange Server I will generate the CSR of the new certificate

          Click on Create CSR

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          Choose SSL certificate type and make sure you choose Mail.domain.com as CN

          In the SANs type all of the involved servers (Skype for Business Frontends, Mailbox servers in FQDN and in Hostnames as in the screenshot below). and click on Generate

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          • Go to your CA Server’s CertSRV URL and copy the CSR code there to generate the new certificate.
          • Import the new certificate to the current server, then export it in PFX format and import it to all the Exchange Servers you’re planning to use.

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          • After importing the certificate I will verify that I can see the private key

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          Click on the Details and copy the Thumbprint or from MMC right click the certificate > Properties give it a friendly name e.g. (IM) and then from Exchange Management shell you can copy the Thumbprint directly.

          Get-ExchangeCertificate | select thumbprint,friendlyName

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          Now use the previous script to create the setting Override for OwaServer.

          Things you can change are in bold “Name, IM Servername Value, and the Thumbprint value”.

          New-SettingOverride -Name “IM Override” -Component OwaServer -Section IMSettings -Parameters @(“IMServerName=SBG-Pool01.domain.com“,”IMCertificateThumbprint= 28E4B1BA0F2FCB1535AF199F02A64EFC78367F2D“) -Reason “Configure IM”

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          If you enter the server parameter to use a single server you can change that by using. Note that you must not use FQDN but rather only the server’s hostname.

          Get-SettingOverride | Set-SettingOverride -Server sbg-mx01,sbg-mx02

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          This should generate an event ID 112 on Exchange servers involved in the deployment.

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            12. Assign the newly imported certificate to IIS Exchange Back End site

            Once the certificate is in the server store, You will be able to easily find in from IIS and bind it to the Exchange Back End site.

            This is the most crucial step to get IM to work in OWA. Don’t worry about breaking up Exchange Sites or Powershell. If you have added Exchange Servers Hostnames and FQDNs in this certificate then you should be good.

            • Now Launch IIS
            • Click on Exchange Back End
            • Select Binding
            • Click on the 444 port and edit
            • Select the newly generated certificate that has the mail.domain.com as CN. (This certificate must also have all Exchange Servers hostnames and FQDNs set as SANs)

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            Make sure you change the backend cert to the new on all the involved Exchange Servers.

            13. On Exchange: Restart the WebAppPool

            Restart-WebAppPool MSExchangeOWAAppPool

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              14. Log out and sign back in to OWA to Check

              Log out of OWA and back in and check if you are able to Login to IM . It should normally sign you in automatically but in case of an error then you should see it.

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              In case of an error you should see the following.

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              If it works then you should see the presence

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              15. Troubleshooting Methods

              If you follow the above steps correctly then it should work especially when applying the right certificate for your Exchange Back End IIS part however if you face an error then you should do the following steps to troubleshoot the error

              • Set the Eventlog for Instant Messaging on Exchange from Low to High

              Set-EventLogLevel -Identity “sbg-mx01\MSExchange OWA\InstantMessage” -Level High

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              • Look in the following path for errors

              C:\Program Files\Microsoft\Exchange Server\V15\Logging\OWA\InstantMessaging

              • Check the Healthset of the OWA Instant Messaging.

              Get-ServerHealth -HealthSet OWA.Protocol.Dep -Server sbg-mx01 | Format-Table Name, AlertValue –Auto

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              Get-MonitoringItemIdentity -Server sbg-mx01 -Identity OWA.Protocol.Dep | Format-Table Identity,ItemType,Name -Auto

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                Ref

                https://docs.microsoft.com/en-us/exchange/plan-and-deploy/post-installation-tasks/configure-im-integration-with-owa?view=exchserver-2019

                https://docs.microsoft.com/en-us/exchange/high-availability/managed-availability/health-sets?view=exchserver-2019

                Communication, Exchange 2016, Exchange 2019, Skype for Business

                Skype for Business IM integration with Exchange 2016 OWA–Part 1

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                The Story

                A good and detailed documentation is everything we need to implement any kind of project especially if it’s an integration between two different servers that perform different roles.

                And with PKI involved the complications multiply thus a good article write up is what we need.

                Previously I have tried a test lab with Skype for Business 2015/2019 IM Integration with Exchange 2016/2019 and the result was a complete failure and endless search for what’s missing to get IM to work from OWA?

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                ERROR

                Upon completion of the steps mentioned in Microsoft’s Official documentation and after restarting Exchange IIS or OWAAppPool you will see this when you try to login to OWA with your user

                There’s a problem with instant messaging. Please try again later.

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                MS Official Documentation

                In their Official documentation Microsoft says that the certificate in question must be trusted by all the servers involved meaning Skype for Business Frontend and Mailbox Servers.

                Meanwhile this is true, it still would not get the IM to login/work although it might drop the initialize event ID 112 in the event log.

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                Here is what MS says about the certificate.

                Exchange and Skype for Business integration requires server certificates that are trusted by all of the servers involved. The procedures in this topic assume that you already have the required certificates. For more information, see Plan to integrate Skype for Business Server 2015 and Exchange. The required IM certificate thumbprint refers to the Exchange Server certificate assigned to the IIS service.

                REF URL: https://docs.microsoft.com/en-us/exchange/plan-and-deploy/post-installation-tasks/configure-im-integration-with-owa?view=exchserver-2019#what-do-you-need-to-know-before-you-begin

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                Step by Step Deployment

                To do things the way that should get this to work, I will detail steps one by one so we can be sure to get the positive results we are all waiting for when dealing with Exchange and Skype for Business.

                Exchange IM URL 1: mail.domain.com

                Skype for Business Pool FQDN: SBG-Pool01.domain.com

                Autodiscover URL : Autodiscover.Domain.com

                Prerequisites

                1. For Default and Web Service Internal, Your Skype for Business Frontend Server/Pool must use a certificate that is generated from an internal CA which you can use later to generate Exchange’s IM Certificate.
                2. UCMA must be installed (Doesn’t matter if version 4 or 5) both are supposed to work with Exchange 2016.
                3. Local Certification Authority must already be deployed in the domain.

                Configuration Steps – Part 1

                1. On SfB: Set CsAuthConfiguration Autodiscover URL for Skype server to find Exchange Autodiscover
                2. On SfB: Get-CsSite to see what is the current site ID.
                3. On Exchange: Check AutodiscoverServiceInternalURI
                4. On SfB: Create new Partner
                5. On SfB: Create new Trusted Application Pool
                6. On SfB: Create new Trusted Application ID

                Configuration Steps – Part 2

                7. On Exchange: Enable OWA VD Instant Messaging
                8. On Exchange: Enable Messaging on OWA Policy
                9. On Exchange: Create Enterprise Application for Skype Pool.
                10. On Exchange: Create new SettingOverride for Skype for Business.
                11- Generate a new Certificate for Exchange IM
                12. Assign the newly imported certificate to IIS Exchange Back End site
                13. On Exchange: Restart the WebAppPool
                14. Log out and sign back in to OWA to Check
                15. Troubleshooting methods

                Prerequisites

                1- Update or Create Server Default and Web Service Internal Certificate for SfB Pool servers

                The certificate installed on the Skype for Business Pool Frontend servers must be generated from a local Certification Authority which can be trusted by Exchange Server services.

                The Certificate generated for Skype for Business pool as in the below screenshot is generated from my CA and includes the names of the servers:

                • Skype for Business Pool
                • Skype for Business Frontend FQDNs
                • Exchange Servers
                • Autodiscover FQDN
                • Lyncdiscover.domains.com
                • Lyncdiscoverinternal.domains.com
                • sip.domains.com
                • meet.domains.com
                • dialin.domain.com
                • External.domain.com

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                2- UCMA must be installed

                On both Exchange and Skype for Business servers I already have UCMA 4.0 version installed, but if you don’t have it or have an older version then you can’t continue without it.

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                3- Make sure you have a Local Certification Authority deployed in your domain.

                Configuration Steps – Part 1

                1- On SfB: Set CsAuthConfiguration Autodiscover URL for Skype server to find Exchange Autodiscover

                For Skype for Business Server to find Exchange Autodiscover Service point and to be able to authenticate servers we’ll be using the below cmdlet

                This enables both servers to authenticate and share information when needed and without user’s interference.

                Set-CsOauthConfiguration -ExchangeAutodiscoverUrl https://autodiscover.domain.com/autodiscover/autodiscover.svc

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                Ref:

                https://docs.microsoft.com/en-us/powershell/module/skype/set-csoauthconfiguration?view=skype-ps

                2- On SfB: Get-CsSite to see what is the current site ID.

                Getting a site ID will be useful for later use to setup the Trusted Application Pool.

                On Skype for Business Management shell. Type the following

                Get-CsSite

                So the Site ID is 1. I will keep this for later use

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                3- On Exchange: Check AutodiscoverServiceInternalURI

                Specify the AutodiscoverServiceInternalURI for internal Autodiscover service. Make sure it points to your public URL and certificate not the internal one otherwise your users will get a certificate error through Outlook and might cause IM chat not to work.

                The Cmdlet would be

                Get-ClientAccessService | Set-ClientAccessService –AutoDiscoverServiceInternalUri https://autodiscover.domain.com/autodiscover/autodiscover.xml

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                4- On SfB: Create new Partner Application

                On Skype for Business Server, Launch Management Shell and use this cmdlet to add Exchange as a trusted Application to the SfB topology.

                New-CsPartnerApplication -Identity Exchange -ApplicationTrustLevel Full -MetadataUrl “https://autodiscover.domain.com/autodiscover/metadata/json/1”

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                5- On SfB: Create new Trusted Application Pool

                New-CsTrustedApplicationPool -Identity mail.domain.com -Registrar sbg-pool01.domain.com -Site 1 -RequiresReplication $false

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                6- On SfB: Create new Trusted Application ID

                From SfB Management Shell run the following cmdlet .

                New-CsTrustedApplication -ApplicationId OutlookWebAccess -TrustedApplicationPoolFqdn mail.domain.com -Port 5199

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                Finally

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                Click on the link below for Part 2

                Skype for Business IM integration with Exchange 2016 OWA–Part 2