mpick/magrep only search first matching header

[seansweda]

This is easily demonstrated by using either tool to search the "Received" headers, as virtually all messages will have several of them. I figured out this can be worked around via magrep "*:regex" to search all the headers so it's not a show stopper. I realize this may be intentional, but if so I don't believe it is clearly documented in the respective man pages (unlike mhdr which has -M option).

[ashiire]

If this is intentional, an option that modifies this behavior would probably be a good idea.

I believe this is not intuitive behavior and would be in favor of changing it, at least by default, unless there is reason to believe that the performance penalty would be an unreasonable tradeoff for most users.