Some people report never receiving emails on their system from AWPCP or our sister plugin Business Directory Plugin. Here is an article that talks about some possible things to look for, a debugging tip and plugin to use, as well as things to try.
Try an Email Logging Plugin
WordPress Mail Logging plugin allows you to trace all emails sent through your WordPress site, including those sent by AWPCP. This verifies that AWPCP is sending your email as you expect. This is an excellent place to start when debugging email issues. It at least tells you what is happening when you send something. What happens after that depends very much on your server/web host configuration.
Check your Server Configuration
There is a good chance that you have simple configuration issues if you see the emails go out above, but nothing shows in your Inbox. You can try using the SMTP settings in AWPCP (docs: ) to override what your server is doing. If that works, you can be certain there’s a server configuration issue.
If it doesn’t, it’s possible you may be experiencing the dreaded blacklist.
Check if your server is blacklisted
An excellent tool for debugging blacklist issues is MXToolbox (http://mxtoolbox.com).
Check to see if your server is on any blacklists here: http://www.mxtoolbox.com/blacklists.aspx
Use an SMTP plugin for Mail Delivery instead of your server
These days, email servers really don't trust ANYONE they don't know. As a result, using your own server to send email tends to cause delivery problems. It's best to rely on the "big boys" like Gmail, Yahoo or Hotmail to do the sending of your email instead. To integrate that into your website we highly recommend: https://wordpress.org/plugins/post-smtp/
Others may work as well, but we have personal experience with this one and like how reliable it is.