Right now I’m blind to any errors that occur with messages sent from the WordCamp.org web server. This week there was a Core bug that resulted in many (most?) messages being rejected by the receiving MTA, but I didn’t know for several days, until the reports started coming in from users and the CoreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. bug was discovered.
I think two things would help resolve this, but I’m open to whatever suggestions you have.
1) Set the Envelope-FROM to firstname.lastname@example.org instead of email@example.com. I’ve already setup the address.
2) Grant read access to mail.* in the logs directory