Tutorial on how to Enable DKIM in Office 365
Refer to DKIM – Domain Keys Identified Mail to understand how DKIM works prior continue the steps below
DNS Records for DKIM
Connect to Exchange Online to generate the DKIM records (CNAME) for yongkw.com
$DomainName = "yongkw.com"
New-DkimSigningConfig -DomainName $Domain -Enabled $true
WARNING: The config was created but can't be enabled because the CNAME records aren't published. Publish the following two CNAME records, and then enable the config by using Set-DkimSigningConfig.
selector1-yongkw-com._domainkey.M365x521231.onmicrosoft.com
selector2-yongkw-com._domainkey.M365x521231.onmicrosoft.com
Domain Enabled
------ -------
yongkw.com False
Add CNAME to DNS Server
Add the following CNAME records to DNS Server
selector1._domainkey CNAME selector1-yongkw-com._domainkey.M365x521231.onmicrosoft.com
selector2._domainkey CNAME selector2-yongkw-com._domainkey.M365x521231.onmicrosoft.com
Verify that both CNAME are added successfully
Enable DKIM in Office 365
Enable DKIM in Office 365
$Domain = "yongkw.com"
Set-DkimSigningConfig $Domain -Enabled $true
Verify DKIM is enabled
Get-DkimSigningConfig
Domain Enabled
------ -------
M365x521231.onmicrosoft.com True
yongkw.com True
Verify DKIM record
Verify DKIM record is added with nslookup
C:\>nslookup
Default Server: one.one.one.one
Address: 1.1.1.1
> set type=txt
> selector1-yongkw-com._domainkey.M365x521231.onmicrosoft.com
Server: one.one.one.one
Address: 1.1.1.1
Non-authoritative answer:
selector1-yongkw-com._domainkey.m365x521231.onmicrosoft.com text =
"v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAxU2BAF9legypielihMjqy/knxeCpB9c/JdNbi4mb+ZmoVVYyb+Ah7dZs+WgRk5lQ5SOHuCZYTl8dXcU5KudTXCtQ8yyQU8J8C4gCoPuJ8QlNc2EUHNKev7FSk/LOlOYcAooofOkyaMwdHOG1LGnU0tqaNc37RguUHxHKt8xDqN/x3djMmdFCgGmkDqFJtXQSG"
"SXXu/coy2QqKkxkb9he2yLMN42Bq7urP+A0/gFFp82cbYTKEdKI4SYaX2vv6SRudyt6IMtR7uEOyxDcpKONcXAgBErRqCJRjFbZQNXzNdA/fF1ByEa7jHtseUqhuEPhaMEbj3hN5EVvFR8RnnLcRQIDAQAB;"
Verify Outgoing Email is signed with DKIM
Verified the Outgoing Email is signed with DKIM properly
- Go to http://dkimvalidator.com/ and send a test Email to the address displayed
- Click on view result and verify the DKIM status = PASS
