The site meets all requirements needed for this plugin and all the mail settings are correct and work properly if you check the mailbox using outlook.
In the wp-admin, all activity on the log shows "Please wait 5 mins to check mail again!" and the last check notice always says "Never".
I'm not getting any errors either displaying in the wp-admin when using check now, or in the activity log other than the wait 5 mins.
Is there something else I need to try or check to get this working correctly?