Sure, if he is alleged to have sent an incriminating email, the headers should be published along with the exact contents so that the public may judge for ourselves. This was done for the Clinton 2016 emails that clearly showed undemocratic interference in the primary elections. So, the fact that they haven't been published in this case does make the whole story less believable. The journalists involved this time probably aren't as smart as Wikileaks, but that's no reason their reporting shouldn't be held to the same standard.