The ‘Traffic not accepted from this IP’ error usually occurs when emails are sent from IP addresses that have a low reputation. These are often used by new Microsoft 365 customers or those using the trial version.
In some cases, it may occur if you’ve sent emails previously without properly setting up SPF, DKIM, or DMARC records.
Resolving the Error – Solution
The ‘Traffic not accepted from this IP’ error message is not a direct outcome of any settings in your SMTP plugin like Easy WP SMTP, but rather, it’s generated by Microsoft.
To resolve this, you can begin by delisting your domain or IP address by filling out the Microsoft support form. If you’re using Office 365, we’d also recommend reaching out to Microsoft Support.
For more information on how to fix this error, please see Microsoft’s official documentation.