supersymmetrical

Any advice?

Actually I figured out: if I put any, and I mean really ANY url inside the body of the email, it will be not sent.
How’s possible?

It never worked, actually.
I don’t have any spam folder, so it can’t be that.
Can depend on the Mail settings of WP?

Wait a sec for the access..

Yes I did, and they’re correctly registered on the Mailchimp List.
It just doesn’t send the email with the file.