SMTP Error: The following recipients failed: XXXX

I'm receiving the following error when trying to send mail using PHPMailer: SMTP -> ERROR: RCPT not accepted from server: 550-Verification failed for 550-No Such User Here 550 Sender verify failed SMTP Error: The following recipients failed: XXXX. How can I fix this?

This error can be caused by a few different things. You can get a better idea of the reason by adding the following line to your PHPMailer script:

$mail->SMTPDebug = 1;

Once you do that, you can check the following things that may be causing the error:

1.) A corrupt class.phpmailer.php file. You can download the latest version from SourceForge here.

2.) The error may be caused by protection put in place by your ISP. Check with them.

3.) It could be a problem with the recipient's/sender's email addresses.

4.) Set SMTPAuth to true for PHPMailer class.

5.) Comment out the following line in your PHPMailer script: $mail->isSMTP();