Ugh. It looks like the way Mail::Address::format() uses it, new('','') is
most correct. New('<>') is definitely incorrect, though new('') will work.
Can you please come up with a test that shows that new('<>') is incorrect? I'm not going to just blindly apply this patch without a test to show exactly what you're trying to achieve (that's not to say that Ask won't apply the patch of course).
I have code that checks for the <> envelope sender, and it works fine, so I'm wondering who's misunderstanding what here.
Matt.
