[ILUG] formail rule to copy all mail from aspecific sender to another mbox ?

[Declan Grady]

Hi folks,
my formail skills are minimal, to say the least.
I have a number of mbox files, and want to rebuild a lost "sent" folder 
from them.

I want to pick out the mails from a specific sender, and either save 
them all into another one mbox file, or send them back to the sender again.

I'm sure its possible using formail and a rule to match the sender, but 
havent a clue how to go about it.

Suggestions ?

Thanks,
Declan