Transferred domain not recognized by Squarespace; how to verify?

Hi all, 

We recently switched our domain from Site A to Site B. Both sites are currently live. We are currently trying to verify the domain name so that we can use the email campaign feature. The domain name was originally from Dreamhost and was transferred to Squarespace. In the 7.1 guide, it says that Squarespace domains are automatically recognized and verified. However, for the email campaigns for Site B, it still asks us to verify what should be a Squarespace domain.

Is there a specific procedure to verify a domain in this kind of situation? Or is this something that needs to be fixed by support (i.e. Squarespace doesn't recognize the domain as its own)?

Thanks in advance.