5 つ星中 3つの評価を受けています

It's not exactly what i expected from such addon.. it would be nice to update it to copy "full headers" .. .

5 つ星中 5つの評価を受けています

It copies the total header of the email into the clipboard. IMO, it is far from a user-friendly output, but because there is no equivalent nor a similar extension available: 5*

wishes: option for specifying optional fields to copy (From, To, Subject, Date)