Tuesday 6 August 2024

 

How to Configure DKIM for a Custom Domain in Office 365

Enhancing Email Security with DKIM in Office 365


DomainKeys Identified Mail (DKIM) is a crucial email authentication protocol that helps verify the legitimacy of an email sender's domain, ensuring that email content remains unaltered during transit. By enabling DKIM in Office 365, organizations can significantly enhance their email security and improve deliverability. This article provides a detailed, step-by-step guide on setting up DKIM for custom domains in Office 365.

What is DKIM?

DKIM adds digital signatures to outgoing emails, allowing receiving servers to validate the message's origin and integrity. The process involves creating a private key associated with your domain name, which is then used to sign outgoing emails. The receiving mail servers use the public key published on DNS to verify these signatures, ensuring that the emails are genuine and not spoofed.

Step-by-Step Guide to Setting Up DKIM

Step 1: Create Office 365 DKIM Keys

1. Sign in to the Microsoft 365 Security Center:

- Navigate to the Microsoft 365 Security Center and sign in.

- Expand Email & Collaboration and click on Policies & Rules.

2. Access DKIM Settings:

- On the Policies & Rules page, select Threat Policies.

- Scroll down and under Rules, click on Email Authentication Settings.

- Click on DKIM and double-click on your custom domain (e.g., Cloudomega.site).

3. Generate DKIM Keys:

- Click on Create DKIM Keys to generate the signature keys.

- Copy the generated keys to a text editor like Notepad for later use.

Step 2: Add Office 365 DKIM CNAME Records to the Domain’s Registrar

1. Access Your Domain’s Registrar:

- Go to your domain registrar (e.g., Namecheap.com), and navigate to the advanced DNS settings.

2. Add CNAME Records:

- Add the two CNAME records copied from the Microsoft Security Center.

- Refresh the DNS settings page and return to the Microsoft 365 Security Center.

3. Enable DKIM:

- Enable DKIM for your Office 365 domain and click OK.

Step 3: DKIM Record Check

1. Verify DKIM Records:

- Visit [Mxtoolbox.com](https://mxtoolbox.com) and select DomainKeys Identified Mail under All Tools.

- Input your domain name (e.g., Cloudomega.site), use Selector1, and perform a DKIM Lookup.

2. Check Selector2:

- Perform the lookup for Selector2. If no DKIM record is found, return to the Microsoft Security Center and rotate the DKIM keys.

- Repeat the DKIM lookup on Mxtoolbox after rotating the keys.

Step 4: Verify with Message Header Analyzer

1. Send a Test Email:

- Send an email from your Office 365 mailbox to an external address.

2. Analyze Email Headers:

- In Outlook, view the message details by clicking the three dots and selecting View Message Details.

- Copy the message details and visit [mha.azurewebsites.net](https://mha.azurewebsites.net).

- Paste the message details into the analyzer and click Analyze Header. A successful configuration will show DKIM=pass.


By following these steps, you can ensure that DKIM is correctly configured for your custom domain in Office 365, enhancing your email security and improving deliverability.

Conclusion

Configuring DKIM is an essential step in securing your organization's email communication. It helps prevent email spoofing and ensures the integrity of your emails, thereby fostering trust with recipients. By following this guide, Office 365 users can efficiently set up DKIM for their custom domains.


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Monday 27 February 2012

Troubleshooting issues with Exchange ActiveSync

Original Link Here


This is really a nice link to troubleshoot Exchange ActiveSync issues, just make sure that you have IIS logging enabled..



IIS 7
  1. In IIS Manager, expand the server name i.e. ExchangeServer (Contoso\Administrator)
  2. In the Features View, double click Logging in the IIS section.
IIS 6
  1. In IIS Manager, right click the web site name (for most it should be Default Web Site) and chooseProperties
  2. Click on the Web Site tab.
You can use a number of queries as per your requirement and can take it in a nice HTML format as well..

There is yet another site that talks about common error codes in Exchange Active Sync along with there resolution

I’ve been troubleshooting Exchange ActiveSync issues on WP7 for a while and thought I would collate all error codes from my personal notes.
You won’t see any official Microsoft documentation supporting these steps, so use it at your own risk.
ErrorSolution
0×85010014Another website other than the “Default website” with host header value same as OWA url
Improper authentication and settings on virtual directories
Allow inheritable permissions were unchecked on user’s properties.
0x80072F0DInvalid certificate on the server
Root certificate missing on the device
0×85010013Re-install CAS role along with the latest Service Pack and update rollups
Set AllowNonProvisionableDevices $true
0×85030027Allow inheritable permissions were unchecked on user’s properties.
Microsoft Server ActiveSync directory corruption. Recreated it
0x80072f0dRemoved HTTP redirect from the Microsoft-Server-ActiveSync
virtual directory from all the exchange boxes
Certificate missing external URL
0x80072F17Allow inheritable permissions were unchecked on user’s properties.
Invalid certificate on the server
Root certificate missing on the device
0x80072f05Root certificate missing on the device
Invalid certificate on the server
0x80072EE2Port 80 Blocked from CAS to MBX server
Certificate missing external URL
0x86000c0aAllow inheritable permissions were unchecked on user’s properties.
0×85010017Allow inheritable permissions were unchecked on user’s properties.
0X85010019Issue with invalid certificate
0×80070057Recreate Autodiscover virtual directory

Monday 2 January 2012

Record your PowerShell sessions


In-case if you want to record your session in PowerShell and wants to take output in a text file for each and every steps that you have done in PowerShell,  below are the steps


In PowerShell run the following command (Change location to wherever you would like)


Start-Transcript c:\Powershell.txt –Append


Now use PowerShell as you usually would, once you are done with PowerShell run the following command 


“Stop-Transcript” (without quotes)


If you now open the “PowerShell.txt” you will see everything you have just done in your PowerShell session.


********************************************
Windows PowerShell Transcript Start
Start time: 20120102173323
Username  : PowerShell User
Machine      : Windows 2008 R2 (Microsoft Windows NT 6.1.7600.0)
********************************************
Transcript started, output file is c:\MySession.txt
[PS] C:\>Get-Mailbox –Identity Daniel


Name                     Alias                ServerName
—-                         —–                 ———-
Daniel                      Dan                  Exchange2010


[PS] C:\>Get-User -Identity Daniel -RecipientTypeDetails


Name               RecipientType
—-                   ————-
Daniel                MailUser


[PS] C:\>Stop-Transcript


Happy Recording :-)