Go to the KSN2 NCEPT page list
linked from this post. Scroll down the KSN page until you see the table that MJ has a screenshot of on the post. The screenshot is cut off but if you go farther down the KSN page you'll see the names of the NCEPT HR points-of-contact for each region. Use Outlook to pull up their FAA email address based on their name.
They had an MOU specifically saying the
confirmation that they received your ERR could be emailed instead of snail-mailed, I don't think it affected sending the ERRs in. But I've sent in paperwork to three different regions and all three accepted my email without complaint.