Automatically flag spam posts containing a certain string?

I’ve been getting a lot of spam posts containing links to a particular domain. These are not getting blocked by the anti-spam tools.

Is there some way to specify a string as a trigger to automatically delete and block the user? or at least to automatically flag it as spam?

Yes, the watched words feature can be used to automatically flag or even block posts containing certain strings. There’s more info about it here: Watched Words Reference Guide

Thanks! Just what I need.