It's possible other plugins can interfere, yes. Depending on how they manipulate the WordPress wp_mail function and if they apply filters to it.
Do the User Notifications work? Is it only the Admin Notifications that don't work? Have you tested using different email addresses that use unrelated domain names such as a @gmail.com or @yahoo.com email address?
If the User Notifications are working and the Admin Notifications are not then it's not an email issue, it's going to be related to where you are sending the email. If emails aren't being received to an email that uses the same domain name as the site, it's going to be a web server configuration issue.
Posted 10 years ago on Tuesday November 8, 2011 | Permalink