For 1&1 IONOS Linux and Windows servers with a fixed IP address
To customize the reverse mapping for the IP address of your 1&1 IONOS Linux or Windows server.
A correctly set reverse mapping is particularly important for reliable operation of your own mail server.
Please note: Since no fixed IP addresses are assigned for Web Hosting packages and managed servers, this guide is not applicable for these product groups.
Log in to 1&1 IONOS.
On the 1&1 IONOS home page, select Server Administration > IP Addresses.
Select the IP address for which you want to set the reverse entry and then click Reverse Mapping.
Enter the domain for which the entry is to be set in the Reverse Mapping field and click OK.
Please note: It may take up to 72 hours before the settings are visible on the World Wide Web. For more information, see the DNS Change Duration article.