myorigin = /etc/mailname
append_dot_mydomain = no
relayhost = outgoing.mit.edu
-mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 10.5.128.0/24
+mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 18.4.58.0/23
mailbox_size_limit = 0
recipient_delimiter = +