I too am using Yahoo and I am having the same issue. Customers are not receiving emails, neither are test emails sending anymore. I have deactivated and reactivated the WP Mail SMTP plugin and reconfigured the setting. I can not seem to find the issue. Please help.
This is the error message I received…
Heads up! The last email your site attempted to send was unsuccessful.
Email Source: WooCommerce Cart Abandonment Recovery Mailer: Other SMTP SMTP Error: Could not connect to SMTP host. Failed to connect to serverSMTP server error: Failed to connect to server SMTP code: 111 Additional SMTP info: Connection refused
For more details please try running an Email Test or reading the latest error event.
