Most TXT records can have up to 255 characters. For TXT records that include more than 255 characters, DNS adds multiple strings together in a single record.
If you’re using a 2048-bit DKIM key, you can’t enter it as a single text string in a DNS record with a 255-character limit. Instead, take these steps:
- Split the key characters into multiple text strings.
- Put each string inside quotes.
- Enter the strings one after another in the TXT record Value field at your domain provider.
In this example, a long DKIM key is split into two text strings, and each string is inside quotes:
"k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAraC3pqvqTkAfXhUn7Kn3JUNMwDkZ65ftwXH58anno/bElnTDAd/idk8kWpslrQIMsvVKAe+mvmBEnpXzJL+0LgTNVTQctUujyilWvcONRd/z37I34y6WUIbFn4ytkzkdoVmeTt32f5LxegfYP4P/"
"w7QGN1mOcnE2Qd5SKIZv3Ia1p9d6uCaVGI8brE/7zM5c/zMthVPE2WZKA28+QomQDH7ludLGhXGxpc7kZZCoB5lQiP0o07Ful33fcED73BS9Bt1SNhnrs5v7oq1pIab0LEtHsFHAZmGJDjybPA7OWWaV3L814r/JfU2NK1eNu9xYJwA8YW7WosL45CSkyp4QeQIDAQAB"
You can also try:
- Using a 1024-bit key by selecting that option when you Get your DKIM key in your Admin console.
- Contacting your domain host to find out whether TXT records with more than 255 characters can be supported. If they are, you can update your DNS record with a 2048-bit DKIM key by following the steps in Get your DKIM key in the Admin console.
We recommend adding no more than 49 TXT records at your domain provider because this is the maximum number supported by most domain providers.
