What can be found in /etc/hostname on phab1001.eqiad.wmnet [2620:0:861:102:10:64:16:8]? Ī̲ can bet that its content is currently “localhost”. And what is the argument to domain in /etc/resolv.conf? Unlikely there is such line at all.
Putting the machine’s individual name and the domain name into relevant settings is one of first tasks for a system administrator who creates an Internet server. When one sees “Message-ID: <⋯@localhost.localdomain>”, an immediate conclusion is that the message originates from a box where a lazy admin works.