Why it works
A subject line is truncated by width, not by character count.
The preview line beside it is a second line of space most senders waste.
Between them you get one specific statement, or you get two vague halves.
- Use it when
- Always, and especially when your preview text repeats the subject.
- Skip it when
- Never. It costs one minute per send.
- What to watch
- What survives the cut on a phone, and whether the preview line adds anything.
- What it costs you
- Being specific means committing, and a committed subject can be wrong.
Put your own numbers in
There is no figure here for what this does. Nobody knows what it does on your list.
Subject Line CheckerAlso in Convert
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A preview renders your mistakes exactly as faithfully as your design.
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