I commented on a WPMUDEV post and clicked the follow option.
I received an email asking me to subscribe to the commets on the blog:
You recently followed one of our posts. Awesome! From now on we'll let you know when new comments are posted.
To activate, click "Confirm Follow" below.
Blog Name: WPMU DEV Blog
Blog URL: https://premium.wpmudev.org/blog
However, when I clicked FOLLOW I encountered a message that the subscription could not be activated.
I am confused.