A DomainKeys Identified Mail, also known as DKIM, gives an organization the opportunity to take responsibility for a message while it is in transit. The message is signed with the organization's certificate and a signature is added to the email headers.
Many email clients (such as Yahoo!, Gmail, Outlook and others) will check for a valid DKIM signature on incoming email as a means of recognizing the originator. When a mail server receives an email it assesses the DKIM header and then performs the following tasks:
- Retrieve the public key from the DNS of the sending domain (re: example.com if the sender is firstname.lastname@example.org)
- Use the key to decrypt the signature and verify the content
In that sense DKIM is a means of increasing the deliverability of your email campaigns and your sender reputation, as it allows you to let the receiving mail server verify your reliability.
Moosend supports setting up DKIM on your sender accounts, but requires that you have control over the DNS settings of your sending domain. When you setup your sender account, you can ask your administrator to setup your DKIM records by doing the following:
1. Click on the Accounts button, located on the top right side of your Moosend account.
2. Click on the Senders button on the menu that appears.
3. Check which of your sender accounts have a valid DKIM signature.
Ticked boxes under the SPF / DKIM column indicate sender accounts with valid SPF and DKIM signatures respectively.
4. Click on the sender email address whose DKIM record you want to set up.
5. Copy & paste the necessary information to your domain's DNS records.
Note that depending on your hosting provider you may need to make small changes to the provided records.
Furthermore, it is important to remember that at this point and in order to finalize the process, it might be necessary that you wait anywhere between 30 minutes to 48 hours before you can move to the next step. After the waiting time is over, visit the page once again and proceed with the final step below.
6. Come back to your Moosend account, and click on the Verify DNS records button to complete the verification.
There are a lot of information available and you can even find informational articles on Wikipedia about DKIM.