Deactivating for a specified authority and/or selector means a key won't be used for signing email anymore, even if they are valid.
The domain authority name you want to deactivate. Must be a valid domain
The selector you want to deactivate for the domain key. Must be a valid dot atom
curl -i -X PUT \ -u '<username>:<password>' \ 'https://api.mailgun.net/v4/domains/{authority_name}/keys/{selector}/deactivate'
A 200 response
{ "message": "domain key deactivated", "authority": "authority.domain.tld", "selector": "selector", "active": true }