I have an existing journey in journey builder. The emails it sends now have to exclude people present on another data extension. Having never used exclusion scripts before, what would I need to write to exclude subscribers who appear in another DE?
An exclusion script is simply simply with certain conditions). Take for example, you want to exclude certain subscribers from a send, you can simply use this:
(ROWCOUNT(LOOKUPROWS("ExclusionDE", "EmailAddress", emailaddr)) > 0)
This assumes that you are currently compiling the subscribers you want to exlude in the
ExclusionDE. The script just check against email address to see if they are present. If they are, they will not be sent the email.