https://porkchop.devel.redhat.com/fedora-updates/show.py?pkg=ypserv-2.13-7&update=Final appears to have lost the submitter, which makes sending the mail blow up.
This update was impored from the old updates 'list' file, which is why it never had an email address associated with it. I added a fix into the system which will assign the update to the person who is requesting it to be moved if there is no email address already included. I reset the 'sent' flag with this update, so feel free to re-send.