Relevant Products: Exclaimer Cloud - Signatures for Office 365
Yes, it is possible to apply a signature based on a recipient domain, but exclude a specific recipient in that domain.
This is because inclusions are processed before exclusions. When sending a message to a recipient in the included domain, the conditions of the inclusion will be met and the signature will be applied if the specific email address is not specified in the exclusion.
If you send a message to a recipient that has been specified in the exclusion, the exclusion overwrites the inclusion and the signature will not be applied.
To apply a signature based on the recipient of the message, see our How do I apply a signature based on the recipient of the message? article.
To exclude a signature based on the recipient of the message, see our How do I exclude signatures from being applied to emails sent to a specific address or domain? article.