If a domain shows "missing MX records", appears inactive, or you're not receiving replies:
First confirm with mxtoolbox.com — in many cases the records are actually set correctly.
If the records genuinely aren't resolving, this is something we fix on our side. We manage your domain's DNS, so please don't add nameservers or records yourself.
If the domain is on a .online, .xyz or .site TLD, the cause may be a registry-level suspension rather than a DNS problem — see My domain shows "MANUALLY DISABLED".
Send support the affected domain names and we'll resolve it. If replies are missing specifically, also confirm your mailboxes are still connected to your sequencer / Master Inbox.