ATT DNS contact

Hi all,
Apologies for the spam, but if anyone has a contact for AT&T that can help with DNS on the list could you please reach out to me off list? I’m seeing failures to send messages to addresses due to a bogus DNS failure on your end:

host[] said: 554
5.1.0 has no MX or A record (in reply to MAIL FROM command)

However, the domain does have a valid, published MX record. Adding a root A record for the domain allowed me to work around the issue, but shouldn’t be necessary.