SmarterMail Ent v15.4.6151

We have a customer that joined up with MailChimp.  The emails were going into Junk E-Mail, and they wanted to whitelist them.  Basically, it's to and from the same user, so a typical whitelist wouldn't work, so I figured I'd use a Content Filter and move to Inbox on the email header.  MailChimp uses: "X-Mailer: MailChimp Mailer - **CIDc42a754cadaa98406eba**" in the headers, so I tried just "X-Mailer: MailChimp Mailer *" with wildcards in the content filter, and it doesn't seem to be working.

 

Any ideas?