We use wordpress for our intranet site at my company, and Subscribe2 to ensure all staff are notified of new posts. This site is hosted internally on our own LAMP server, so I can analyse the mail logs myself.
Each staff member is registered with the site, and automatically added to Subscribe2.
Typically our posts are set to autopublish at 6am the following morning.
Recently some staff have noticed that they are not receiving these emails. Looking in the mail logs, I can confirm that only about 400 emails were actually sent (2 of which bounced). The missing subscribers are not being blocked, they just don't appear in the mail log to begin with.
I have checked and confirmed that the users being missed are subscribed correctly, and that their email addresses are correct.
It appears that the subscribers that are being missed are those most recently added to the site.
I have tried sending emails in batches of 50, 1, and 0 (altogether). I recently upgraded the SubscribeTo plugin from version 7.1 to 8.8.
I also (just) installed the "email log" plugin to see if that gives me any additional info.
Just wondering if there is some better way of debugging this problem?