How to setup your Sending Domain?

Sending domains will match the FROM address of the email campaigns and
will add proper DKIM signatures to the email headers, thus increasing the chances of inbox delivery.

With sending domains you can verify the authenticity of the domain used in the campaigns FROM email field.
Verification is very simple, it involves adding just two DNS TXT records for the domain used in the FROM field of a campaign.
Once a sending domain is verified, all future campaigns sent from the verified domain will be DKIM signed and will pass SPF validation, thus giving a higher inbox delivery rate.

Step 1: Go to “Sending Domains” in the Domains sections.

Step 2: Click on Create new, to create a new sending domain.

Step 3: Simply add your Domain Name and Click Save Changes. It will automatically generate the DKIM private and public key

After you click save changes, you will be redirected to Verify your domain section, where you have to verify your domain.

Step 4:

After you have updated the following records into your DNS records, click on verify DNS Record. You have successfully set up a sending domain.
Please note that it can take up to 48 hours for DNS changes to propagate. If verification fails now, please try again later.

You should use sending domains only if your delivery servers do not sign your emails with DKIM, because the only purpose of sending domains is to identify the domain from the “FROM” or “Return-Path” of your headers and generate a dkim signature for them.
Like in the above case, if your domain is b.com and you send emails from [email protected], then you can add a sending domain (b.com) for which primailer will generate the dkim records (you have to add the public key into your dns records, as a TXT record).
Once the domain is confirmed, each time when mailwizz finds an email that contains the domain b.com in its FROM/Return-Path headers it will append the right DKIM signature.