Guide per DNS host

Set up the MX record at netcup

MX records decide which servers accept mail for the domain. At netcup they are preset for its own mailboxes; as soon as mail should go to another provider they are replaced in the DNS editor. This guide shows the values, the way through the netcup control panel and the pitfalls of a switch.

The MX hosts of netcup

netcup lists the MX hosts for its own mailboxes in the email settings of the control panel; they differ per package. With its own name servers netcup sets them automatically, with external name servers they must be created there.

Switching to Microsoft 365 or Google Workspace

Microsoft 365 expects exactly one MX pointing to your-domain-com.mail.protection.outlook.com (the admin center shows the exact value), Google Workspace one MX pointing to smtp.google.com with priority 1. Remove the old netcup MX records, otherwise mail keeps arriving at netcup depending on priority. Lower the TTL before the switch and create the mailboxes at the new provider first so no mail is rejected.

How to add the MX record at netcup

The way to the netcup DNS editor:

  • In the netcup Customer Control Panel (CCP) open "Domains" and select the domain.
  • Switch to the "DNS" tab and choose "Add new record".
  • Type MX, host name @ (apex domain), value: the host name of the mail server without a trailing dot, plus the priority. For several mail servers create one entry each with its own priority and remove old MX entries.
  • Enter host (@ for the apex), type and destination, then "Save DNS records".

Typical mistakes at netcup

  • Trailing dot or missing priority: some editors require both, others reject them.
  • Old MX records not removed after the switch.
  • MX pointing to an IP address or a CNAME instead of an A record.
  • Mailboxes not yet created at the new provider, mail is rejected.

Verify and keep an eye on it

After saving, the change at netcup usually applies within minutes. The checker below queries the authoritative name servers and shows right away whether the MX record is read correctly. DomainWarn keeps checking the record afterwards and alerts you when it changes or disappears, for example after a migration or one click too many in the DNS editor.

Frequently asked questions

Can I keep mailboxes at netcup and use Microsoft 365 only for sending?
Receiving and sending are separate: MX records decide receiving, SPF and DKIM decide sending. Both can be mixed, but a clean switch is usually simpler.
Which priority is right?
The lowest number wins. With one mail server 10, with several 10 and 20. The value only has relative meaning.
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The same guide for other hosts