Subscribe by email not really working on Multisite

We are having an issue where it seems like everyone's emails are sitting in queues pending. I have people complaining that the emails are not going out on their sites.

I do realize that email can be a bigger problem than just this plugin so I am hoping that one of your techs can verify that everything is in proper order from any database issue or other ailment that may prevent this plugin from sending out emails.

I have activated support access.

Thank you kindly for helping. Maybe your expertise can help determine how I can best troubleshoot this.