In some email-clients, when you copy the Message-ID to the clipboard it surrounds in (or perhaps, doesn't strip) angle brackets. When pasting this into the mail archive search, search fails to find the message and this happens often enough so as to be annoying. The fix is trivial.
Discussion of similar problem in the commitfest app:
Interesting - we also had a similar fix in 9b7e9b59 for the archives, but that one only deals with the URLs and not the search box. Makes much sense to do it in the search box as well, so applied. Thanks!
Actually, before I sent this. It's also broken because it redirects to bad URLs if there are spaces in it. Or if there is just one of the two, e.g. it has < but not >. All those now generate 404s, which is not good.
This patch needs to be in sync with the callers of that API as well as the code that actually views entries in the archives before it can be safely applied.