How to deal with SMTP "Data Not Accepted" Error ?
If you ever receive an error message stating Data Not Accepted while trying to connect through SMTP settings, then you might need to check on the following details below for solving it. This happens when the SMTP server rejects the mail for certain reasons.
If your Server Doesn't Allow Different Sender and Usernames
Some servers require that the From email address is the same as the email address used to authenticate. Check the from name and match it to the username you use to login to your SMTP server.
The File size of your message might is too Large
Some servers reject a message if the body is too large. HTML emails, in general, are bigger than normal text messages but its recommended to decrease the size by removing some content or by disabling embedded images.
The receiver might be blacklisted or blocked.
Sometimes certain email addresses are blocked and to prevent getting blacklisted, the server rejects your message. The best resolution is by changing the sending method.
In case of any temporary issue
Sometimes the email server responds with this error if some limits have reached or you’re sending “too fast”. Please pause your campaigns for a while and try again later. If you are sending via Amazon SES you must have verified the from, reply-to and bounce address you are using in your mailings.
If this doesn't solve your issue, feel free to contact SalesHandy support at email@example.com.