On Thu, 29 Aug 2013 00:55:29 +0200 Michael Schaap wrote: > On 29-Aug-2013 00:30, John Hardin wrote: > > On Wed, 28 Aug 2013, Michael Schaap wrote: > > > >> Hi, > >> > >> I'm getting loads of fake LinkedIn invites, most of which aren't > >> caught by SpamAssassin. > >> Does anyone have a good SpamAssassin rule to catch those, while > >> letting real LinkedIn invites through? > > Do they fail SPF or DKIM? > > > The "From:" header is at linkedin dot com, but the envelope sender is > a random address
I'm guessing that legitimate linkedin mail has something other than a random address in its envelope sender.