Can an MX record point to a CNAME?

No. RFC 5321 requires MX targets to be hostnames with A or AAAA records. Some receivers tolerate CNAMEs, but others will not deliver.

A single MX record with priority 0 and target "." says the domain accepts no mail (RFC 7505). Use it for domains that only send or are unused.

MX lookup

Look up MX records and see which provider receives mail for a domain.

MX records tell other mail servers where to deliver email for your domain. A missing or broken MX means you cannot receive mail, including bounces and DMARC reports.

MailVakt lists your MX hosts by priority, checks that each one resolves, flags MX targets that are CNAMEs, recognises null MX for domains that do not receive mail, and identifies the mailbox provider.

Questions

Can an MX record point to a CNAME?: No. RFC 5321 requires MX targets to be hostnames with A or AAAA records. Some receivers tolerate CNAMEs, but others will not deliver.
What is a null MX?: A single MX record with priority 0 and target "." says the domain accepts no mail (RFC 7505). Use it for domains that only send or are unused.

Fix this from ChatGPT or Claude

MailVakt is an MCP server, so your assistant can run this check itself, read the findings and walk you through the DNS edit. Ask it:

“Look up the MX records for example.com, tell me which provider receives its mail, and flag anything broken.”

Claude: Settings → Connectors → Add custom connector, then paste https://mcp.mailvakt.com/mcp.
Cursor and other MCP clients: add the same address as an MCP server. Setup details.

Checks are free and need no account. Sign in only to collect DMARC reports for a domain.