Command note: a merge field that fails doesn't error. It just prints. We sent a campaign where the greeting rendered as "Hi ," for part of the list. No bounce, no warning, nothing in the logs. The field was simply empty on those contacts, and the message went out anyway looking like a template somebody forgot to finish. Three ways this goes wrong: • The token is misspelled or points to a field that was renamed, so it renders as raw text • The field exists but is blank on a chunk of the list, so you get the punctuation with no name • The field only fills from one form, and half the audience never saw that form What we do now before anything goes out: 1) Check fill rate first — count how many contacts in that exact audience have the field populated 2) Write a fallback for every token, and assume the fallback will be the one that prints 3) Send the real message to a test contact with the field deliberately empty, then read it 4) If the fallback reads badly, rewrite the sentence so the field isn't load-bearing 5) Publish only to the segment where the data actually exists The fix is almost never better data. It's usually a sentence that works either way. A merge field is a promise about your data. Don't make one you can't keep.