Hello,
I have a requirement to setup DKIM for one of our vendor. They use some tool to send emails from their environment and use our email address. The issue is not caused when emails are sent to us, but when the emails are sent to other domains.
I checked in Exchange Admin Center>>DKIM and can see our internal domains added there. I don't think we can add an external domain in accepted domains and then generate a DKIM key.
I am new to these requests and may be my questions looks a bit illogical. Any help or suggestion is greatly appreciated.
We are using Exchange Online