How an MX record works
An MX record — mail exchanger — tells every other mail server on the internet where to deliver messages addressed to your domain. When somebody writes to you, their provider looks up the MX records published on your name and connects to the host listed there. Your website’s address plays no part in this. Mail and web are routed by separate records, which is exactly why one can be working perfectly while the other is dead.
A domain normally publishes more than one MX record, each carrying a preference value. The host with the lowest value is tried first and the rest act as fallbacks if it does not answer. Email providers publish the precise set of records they expect, and the rule is to use theirs in full rather than blending entries from two providers and hoping the priorities sort it out.
Why MX records matter
Email is where enquiries, quotes, invoices, password resets and platform verification codes arrive. A wrong MX record does not announce itself to you: the sender receives the failure, or nothing fails at all and the message simply lands somewhere you never look. Most businesses find out days later, when a customer mentions they wrote and heard nothing back.
They sit alongside the records that protect your sending. Receiving is the MX record’s job; proving that mail claiming to come from you is genuine is handled by TXT records holding SPF, DKIM and DMARC. Both sets live in the same zone and both are lost in the same careless edit, which is why email deliverability problems so often begin in DNS rather than in the campaign itself.
Common mistakes with MX records
The most damaging is a website move. Somebody repoints the nameservers to a new host, the new host generates a default zone containing its own mail records, and company email stops the moment the change spreads. The website looks fine and loads faster than before, so nobody connects the outage to the migration for hours.
The second is leaving a previous provider’s records in place beside a new provider’s. Mail then arrives at whichever server answered, so messages land in two different mailboxes at random and half the team quietly believes the other half is ignoring customers. The third is editing mail routing on a Friday, which turns a small mistake into a weekend of silence.
Getting mail routing right
Copy your provider’s records exactly and completely, then delete anything left by an old provider or created automatically by a host. Before changing nameservers, write the current mail records down and re-create them at the new provider before the switch rather than after it. Once the change is live, send a message from an outside address, then reply to it, because receiving and sending fail independently of each other.
Keep at least one working mailbox on a different domain, and use that address on your registrar and DNS accounts. Being locked out of the account you need in order to repair your mail, because the recovery email is on the domain whose mail is broken, is an avoidable afternoon.