Configure IP Whitelist for Network Devices to Send Mail to Exchange Server without SMTP Auth

This is very easy and is done using a new Recieve Connector. 

Login to the ECP and click Mail Flow, then Recieve Connectors. Create a new Recieve Connector.

Name the connector something descriptive. 

Select Frontend Transport and Custom.

In Network Adapter Bindings leave "All available IPv4" this is only the case if the Exchange Server has a single NIC. It's slightly different if your server has arms in two networks.

In Remote Network Settings, enter the IP's of the network appliances you want to be able to send mail without authentication.

Click Finish.

To test use the following Telnet commands (you run this from a server which is listed as allowed in the new Recieve Connector).

set localecho OPEN mail.domain.com 25 EHLO domain.com MAIL FROM:ise@domain.com RCPT TO:ryan.betts@domain.com NOTIFY=success,failure DATA Subject: Test from Telnet Testing . QUIT

If it's successful it should return a message similar to below.

If you want the server to be able to relay to external domains you must run another command as well.

Change it to reference your Exchange Server and Recieve Connector name, also remember and run it from Exchange Mgmt Shell or it will fail. 

Get-ReceiveConnector "EXSRV\REC CONN NAME" | Add-ADPermission -User 'NT AUTHORITY\Anonymous Logon' -ExtendedRights MS-Exch-SMTP-Accept-Any-Recipient

Update all user "targetAddress" and "proxyAddress" attributes in AD using Powershell for Exchange Hybrid

AD attributes are important when you have a hybrid setup from your on premise Exchange to Office 365, the following script will help retrospectively publish the required objects to your domain users so that hybrid mail flow works correctly.

Review this article for details on AD attributes in Exchange with hybrid connectivity.

http://blog.ryanbetts.co.uk/2018/09/understanding-ad-attributes-in-exchange.html

The following command can be used to export a list of users to a CSV file, you should change the OU path to suit your own environment. Once you have a list of users copy and paste them into a blank text document.

Get-ADUser -SearchBase "OU=Standard Users,OU=User Accounts,OU=Grand Cayman,OU=Company X,DC=domain,DC=com" -prop * -Filter * | Select samaccountname | Export-CSV C:\Users\Administrator\Desktop\Users.csv

The following command will set the "targetAddress" attribute for every user listed in the text file.

The "targetAddress" is used when on premise mailboxes try to send mail to Office 365 mailboxes.

Remember to capatilise SMTP as this will ensure it's the primary email adress. 

Get-Content C:\Users\da.ryan.betts\Desktop\O365Users.txt | % { Set-AdUser $_ -add @{targetAddress="SMTP:$_@companyx.mail.onmicrosoft.com"}}

The following command will append the FQDN, your public domain should be set as the primary so ensure caps are used with SMTP.

Get-Content C:\Users\Administrator\Desktop\O365Users.txt | % { Set-AdUser $_ -add @{proxyAddresses="SMTP:$_@companyx.com"}}

A second pass of the same command will add the additional proxy address which should be tenantname.mail.onmicrosoft.com

Get-Content C:\Users\Administrator\Desktop\O365Users.txt | % { Set-AdUser $_ -add @{proxyAddresses="smtp:$_@companyx.mail.onmicrosoft.com"}}

When you sync the AD to AAD using AD Connect the x500 entry will also appear under proxyAddresses. 

Exchange 2013 SP1: Deleting an Exchange Server from Active Directory using ADSI Edit

I had to remove a failed Exchange Server from Active Directory, the server was not going to be brought back online. This is done using the ADSI Edit tool on one of your Domain Controllers. Open ADSI Edit and right click  on the ADSI Edit icon and select Connect to...

Use the drop down list to select Configuration from the Select a well known Naming Context: list. Click OK.

Now expand;

CN=Configuration/CN=Services/CN=Microsoft Exchange/CN=DOMAIN/CN=Administrative Groups/CN=Exchange Administrative Groups/CN=Servers

And right click on the failed server from the list of Exchange servers and select Delete. You will be prompted to confirm you want to delete the entry, click Yes.

Now if you launch the Exchange ECP and browse to Servers/Servers, hit the fresh icon and the Exchange Server will not be removed from the list.