Google Calendar invite responses can get blocked by DMARC on a “reject” mode. If you have been facing this issue, explore troubleshooting options with PowerDMARC.

“DKIM authentication settings update failed” is a common error that may occur because your email provider is likely having a problem with their DNS records or authentication servers.

DKIM key rotation is the process of updating your DKIM keys. You should rotate your keys periodically—the exact period isn't important, but the process itself is. It's a security measure that helps prevent attackers from impersonating your domain.