I've done some research on DKIM, and just looking for some confirmation.
I was requested to add a DKIM record by a company we contract with to send marketing email (not spam, really).
They asked me to add a txt record: key1._domainkey.mydomain.com.
I want to make sure that mere act of adding this record to my domain doesn't affect any email delivery except possibly help the messages that are signed from the marketing service.
I didn't want some email gateway looking at my regular email, noticing that I have DKIM key associated with my domain, but for some reason have chosen not to apply a DKIM signature to this particular message, so maybe that message should get a lower score, or maybe it's spam.
I'm assuming any gateway concerned with DKIM would only verify the authenticity of a message that's signed with a DKIM signature, but if a message doesn't contain any DKIM signature, no checking if the domain has a DKIM key record.