DKIM key at {selector} is restricted to SHA-1

What it means

The record at selector1 permits only rsa-sha1, which must no longer be used. Signatures made with it have permanently failed evaluation, so this key protects nothing.

How to fix it

Remove the h=sha1 restriction so SHA-256 is used, and rotate the key if your provider still signs with SHA-1.

Check your own domain

This page describes the condition. To find out whether your domain has it, run the DKIM test or the full checkup, which examines every record at once.

Understand it properly

This page covers one condition. For the whole picture, What is DKIM, selectors and key strength, or start at the Health Library.

Where this comes from

We judge this against RFC 8301 section 3.1. Every finding on this site cites the specification behind it so you can check the work rather than take our word for it.

Other DKIM conditions

• No DKIM key found at the usual selectors
• No DKIM key at the selector you gave
• DKIM key at {selector} has been revoked
• DKIM key at {selector} is below the minimum size
• DKIM key at {selector} is only 1024 bits
• DKIM selector {selector} is in testing mode