If that is correct then why is your signature 325x125? And a signature is highest 400x150, some have it as 400x100 aswell.
Arc's signature is a height
of 125, which is less than the limit of 200. The width
is 325, which is less than the limit of 700. Hopefully this helps answer your question?
Edit: I noticed you made a thread here
with some examples. The height (150) and width (400) of your sigs are fine. Some exceed the file size
limit, however. They need to be 120 kb or less.
Let me know if you have any other questions.