yea
KumoMTA can be configured either way.
Could you share the recommended approach or best practices for managing this setup with multiple subdomains?
You offer far too little context to make a deliverability recommendation, from a KumoMTA implementation there’s really no difference between domains and subdomains when configuring DKIM.
Would using a single DKIM key for all subdomains be advisable, or are there scenarios where unique keys for each sub-domain is requird?
Others can respond, if you want my answer detail your use case explicitly and we’ll go from there.
My use case is managing email traffic for multiple subdomains (e.g., xyz.book.com, abc.book.com) to separate clients or campaigns.
Why would your clients want to use a subdomain of yours rather than their own domains?
The clients actually want to use their own domains, but we’ll be managing their email traffic via subdomains of our primary domain (e.g., client1.book.com, client2.book.com)
Define “managing their email traffic”.
Again, I said be explicit.
just like sendgrid do
Is this your first MTA install?
even Esps are allowing it
i can add here 100 sub-domain too
i have installed many times
Sure, but Brevo is just implementing what you configure, they are not proactively assigning subdomains to each of their customers.
so my question still remains the same do i need to create dkim public key for each sub-domain ?
Many ESPs will sign a single key for all their owned traffic. This will create a common reputation indicator for all domains. That may or may not be what you want depending on your sending practices and reputation.
If so, there’s no point regenerating it over and over again, you could just configure a fixed path in the DKIM helper.