Well, not really for dummies, but knowing more about this anti-spam system will help you get your emails into the Inbox. Most of the time, the question is, "should I use DKIM for my email sending..." YES! "Will it ensure my emails get into Inboxes?" NO! But, it helps a ton. DomainKeys Identified Mail (DKIM) is a method for associating domain name to an email message thereby allowing a person, role, or organization to claim some responsibility for the message.
Here is how it works:
- You send an email using your SMTP server.
- Your SMTP server that has authority to send in behalf of your domain adds a DKIM signiture header to your email and sends it
- The destination SMTP receives the email, sees a DKIM signature in the email, and then looks up the public signature on your domain using via DNS
- If the signature in your email authenticates with the public signature in your email, then the email is "good"
Now, saying that the email is "good" means that the destination SMTP knows it is from you, but the destination mail server will still SPAM score your email by the content. DKIM adds a ton of "good" SPAM scoring advantage to your email and thus will greatly improve it's inbox-ability.
So, if you are not using DKIM, use it! Click here is a great link in Wikipedia on the subject
Understand this will not have anything to do with your email sending client, like Outlook or Campaign Enterprise. The system works because it is on a SMTP server level of activity and is based on authority that can only be established by domain owners.