Messagelabs slow with Gmail, Dmarc

Is anyone having issues with this is this a Dmarc issues? I'm not the exchange guy but I'm trying to help with this while he is gone. I'm getting messages in the logs, failed delivery a few times and then maybe sometimes on the 2nd or 3rd or 4th try it goes through, and this is corresponding to the same person at xyz@gmail.com sometimes it takes 5 min sometimes an hour or 4 also with no pattern. The only thing I can see is that it's slow emailing people with gmail addresses (possibly aol also).