I have a campaign that sends email and text message notifications to customers who have missed a monthly payment for our subscription. This campaign is made up of an email that sends day 1 and a text message that sends day 2. A lot of our customers fail to provide an email address to us so our best method is to text. However, with our reporting we can only report on Email deliverability, not text.
So for those who do not have an email address I set up a rule in Marketo that says "If email is blank change to this email address "firstname.lastname@example.org", a dummy email, just so we can report on it. However, I'm noticing the peoples emails change, but the email within the campaign fails to send to this address. It worked in the past, but no longer does. Could it have been blocked by Marketo servers for sending too many times? If so how can I fix?
That's not a dummy email address, it's a mailbox at a real private domain owned by somebody else. You must not abuse domains in this way.
If you want an actual dummy address, use @email.test or @email.invalid. There are RFC-guaranteed reserved domains.