Email notifications are not delivering?

First, please make sure that application notifications are enabled from Job Openings > Settings > Notifications. Also, please ensure that the 'from' address used by our plugin (Settings > Notifications) for the applicant and admin notifications are the same. If there are no issues, then this can happen if you use the default PHP mail service.

To test if there are any issues with your mail provider, please install and activate the plugin (You can remove the plugin after use), Check & Log Email (https://wordpress.org/plugins/check-email), and follow the below instructions.

1. Go to Check & Log Email Settings and check the 'Enable Logs' option and click the 'Save' button.
2. Then go to Check & Log Email > Status and send a test mail. Please don't use the email address which is associated with your site. Preferably choose a mail with the Gmail domain name. If the mail is not delivered, it's not an issue with our plugin but an issue with your email delivery service. In that case, please refer to the 'Suggestions' section. If the mail is successfully delivered, please continue to the next step.
3. Then, submit a test application and go to Check & Log Email > View Logs. Please check the 'Sent Status' corresponding to the applicant mail and check if any issues are being reported. If there are any issues, please provide us with the admin access to look into this issue.

Suggestions

If you use the default PHP mail service, then many limitations or issues can occur due to the default PHP mail service. So, most of the users prefer other mail services(paid and free) for email delivery. You can use a dedicated plugin for handling the mail. For example, WP Mail SMTP by WPForms (https://wordpress.org/plugins/wp-mail-smtp). Also, please refer to 'External Resources' for more solutions regarding your issue.

External Resources:
1. https://kinsta.com/knowledgebase/wordpress-not-sending-emails/
2. https://kinsta.com/blog/free-smtp-server/