These values are compared to the new values retrieved from the received mail. It may sound complicated, but it's really not. Before setting a DKIM signature a sender needs to decide which elements of the email should be included in the DKIM signature. AOL may skip the DKIM check if the SPF check passes… Eventually, every single message sent from Microsoft 365 will be DKIM-signed. DKIM signatures for email from this domain will look something like this:In this example, the host name and domain contain the values to which the CNAME would point if DKIM-signing for fabrikam.com had been enabled by the domain administrator. You should use DKIM in addition to SPF and DMARC to help prevent spoofers from sending messages that look like they are coming from your domain. This DKIM signature reveals which domain was used to sign the email in the encryption process. For instructions on viewing message headers in Outlook, see The DKIM-signed message will contain the host name and domain you defined when you published the CNAME entries.

3600 IN MX 5 contoso-com.mail.protection.outlook.comFor example, if you have an initial domain of cohovineyardandwinery.onmicrosoft.com, and two custom domains cohovineyard.com and cohowinery.com, you would need to set up two CNAME records for each additional domain, for a total of four CNAME records.It's important to create the second record, but only one of the selectors may be available at the time of creation. The variables provided in the DKIM signature are used to determine where to look for this key. It works together with DMARC (and SPF ).Read more about this topic in our article about DKIM signature. When recipients receive your emails, their spam filters automatically poke your domain to see if … You can check any domain name, but I’d check... You will need to edit your domain name’s DNS records to add the records. This means that if you do not set up DKIM yourself, Microsoft 365 will use its default policy and keys it creates to enable DKIM for your domain.Also, if you disable DKIM signing after enabling it, after a period of time, Microsoft 365 will automatically apply the default policy for your domain.In the following example, suppose that DKIM for fabrikam.com was enabled by Microsoft 365, not by the administrator of the domain. If they match, the DKIM was valid.DKIM alone is not a reliable way of authenticating the identity of the email sender. Instead, the process depends entirely on the organization.An example message showing a properly configured DKIM for contoso.com and bulkemailprovider.com might look like this:Bulk Email Provider gave Contoso a public DKIM key.When sending email, Bulk Email Provider signs the key with the corresponding private key. To validate the DKIM signature, the email receiver will run a DNS query to search for the public key for that domain. Since the digital signature stays with the email message because it's part of the email header, DKIM works even when a message has been forwarded as shown in the following example.In this example, if you had only published an SPF TXT record for your domain, the recipient's mail server could have marked your email as spam and generated a false positive result. It's a good practice to have multiple keys so that you can rotate them periodically. This requires coordination between yourself and the third-party in order to set up the necessary DNS records. AOL may skip the DKIM check if the SPF check passes. To Confirm DKIM signing is configured properly for Microsoft 365 Send a message from an account within your Microsoft 365 DKIM-enabled domain to another email account such as outlook. That means you don't need to do anything to set up DKIM for any initial domain names (for example, litware.onmicrosoft.com). When you configure DKIM, you authorize your domain to associate, or sign, its name to an email message by using cryptographic authentication. So, if you have two domains, you must publish two additional CNAME records, and so on.If you are one of our GCC High customers, we calculate For Microsoft 365, the selectors will always be "selector1" or "selector2".contoso.com. The signing domain, or outbound domain, is inserted as the value of the Since both 1024 and 2048 bitness are supported for DKIM keys, these directions will tell you how to upgrade your 1024-bit key to 2048. Instructions for viewing the header for the message will vary depending on your messaging client. The addition of DKIM in this scenario reduces false positive spam reporting. For a quick introduction to SPF and to get it configured quickly, see The DKIM Check tool will perform a DKIM record test against a domain name and selector for a valid published DKIM key record. If you have a Yahoo account, you can also send your email to your Yahoo email address to test DKIM signature. If you don't, it will not align and instead will use your organization's initial domain. Do not use an aol.com account for testing purposes. Specifically, complete all steps in Disabling the signing policy does not completely disable DKIM. If there is "dkim=pass" in your email header, your DKIM signature is ok. What's DKIM and SPF? Verify that DKIM is enabled in server-wide setting at Tool & Settings > Mail Server Settings. After a period of time, Microsoft 365 will automatically apply the default policy for your domain.