Set up the MX record at STRATO

The MX hosts of STRATO

For mailboxes at STRATO the MX records point to smtpin.rzone.de. STRATO sets them automatically with its own name servers; if the name servers are elsewhere, they must be created there.

10 smtpin.rzone.de

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 STRATO MX records, otherwise mail keeps arriving at STRATO 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 STRATO

The way to the STRATO DNS editor:

• In the STRATO customer login open "Domains" and then "Domain administration".
• Choose "manage" next to the domain and switch to the "DNS settings" tab.
• STRATO separates by type: "TXT and CNAME records" for SPF, DKIM, DMARC and verifications, "MX records" for mail delivery.
• 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 the value and save; propagation can take up to an hour.
• For subdomain records such as _dmarc or selector._domainkey put the prefix into the "Subdomain" field, not into the value.

Typical mistakes at STRATO

• 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 STRATO 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 STRATO 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.