SMTP Errors in activity logs

[Beekingo]

Im getting in my activity log some entries like this:

 

"Contact form mail sending failed with a PHPMailer Exception: SMTP Error: data not accepted. (Subject: bla bla bla)"

 

Some are from system username, others from client username.

 

 

Im using amazon SMTP services, all the test i can do everything works fine. Emails works, customer get their emails. No problem at all.

 

I have only these 9 entries with the error and i can't reproduce it by myself. Looks like these comes from some sort of form. The only one i have is the one to submit a ticket and its working fine.

 

Any help? I already opened a ticket but mayne this is faster.

 

Thanks

Cristian

[wapps]

I get this sometime also

[Beekingo]

I get this sometime also

 

Do you ever know where this log entry originates?

[WHMCS John]

Hi,

Please begin your troubleshooting at http://docs.whmcs.com/Email_Sending_Issues#Troubleshooting