Creating a DKIM for Office365
Install OpenDKIM
apt install opendkim-tools
Generate Selectors
opendkim-genkey -D /root -d <domain> -s selector1
opendkim-genkey -D /root -d <domain> -s selector2
Then view the DNS record by running:
cat /root/selector1.txt
cat /root/selector2.txt
Adding the DKIM to DNS
Navigate to DNS
Go to your DNS Provider’s Portal
Create TXT
- Click “Add Record” on the DNS page
- Select a
TXT-Record
- Set the name as
selector1._domainkey
- Set the value as the DKIM selector value from the
/root/selector1.txt
, it should look similar to:
"v=DKIM1; h=sha256; k=rsa; "p=XXXXXXXXXXXXXXXXXXXXXXXXXXXX"
- Click “Save”
Selector 2
Repeat the same steps for selector2
Adding the private key on Office365
Visit the 365 DKIM Page
- Visit the Office365 Admin Portal
Select your domain
- Click the domain that you want to enable DKIM for.
Enable DKIM Signatures
- Change the “Sign messages for this domain with DKIM signatures” toggle to “Enabled”
Upload Key to 365 Admin
- Upload the private keys from the
selector1.private
andselector2.private
files to Office365
Microsoft Managed DKIM
Alternatively, you might want to use the managed DKIM provided by Microsoft which can be accomplished by:
Navigate to DNS
Go to your DNS Provider’s Portal like Cloudflare’s DNS Page
Create CNAME
-
Click “Add Record” on the DNS page
-
Select a
CNAME-Record
-
Set the record like the following with
example-com
andexamplecom
filled in as your domain.
Set the “name” as:
selector1._domainkey
Set the “value” as:
selector1-example-com._domainkey.examplecom.onmicrosoft.com
Selector 2
Repeat the same steps for selector2