The Sonic AutoPOP feature/service hasn't worked for me since about May 24th, 2018.
I have deleted and recreated all my AutoPOP configured profiles after first verifying that the server, port, username, password and related settings for each of them was correct and functional. I thought this might "fix" the problem but, it didn't.
I then contacted Sonic support directly via email and realized after a brief exchange that the Sonic email support staff didn't know enough about "AutoPOP", what it is and how it works to provide any useful feedback or help. It was kind of amusing when they blamed my "third-party" application that I used to TEST and verify the POP settings for the problem!
So, I called Sonic support only to be told that they didn't know enough about AutoPOP and how it worked to be able to help me either, sorry... they said that for any help I would need to go to the Sonic Forums...
So, here I am, hoping to get some real assistance : )