Getting duplicate notification emails for a reply that I've already read

[NeatNit]

This comment was posted 9 hours ago: https://forum.facepunch.com/f/meta/rqfr/Garry-s-Mod-Wiki-links-text/1/#postknqls
I read it and even replied to it 7 hours ago.
5 hours ago, I received an email notification about it.
10 minutes ago, I received another one.

https://files.facepunch.com/forum/upload/767/a2667e1d-5ce4-4bac-a727-03e1532455fe/Screenshot_20180212-025319.png

Both emails are identical.
I think it's clear that I shouldn't be getting an email about a post that I've already read, and even if for some reason one slips by, I should never get two emails for the same post.