One of our people keeps getting an email bounce back when trying to respond to an email sent from a client. The error is a 550. I have gone through the link that is suggested to find out why but have found no solution. The email account is set up with the SMTP authentication. There isn't any crazy wording that look like spam. It is happening with almost every email reply they send out. If they copy and paste the same exact content it goes through but that is ridiculous to have to do every time they want to send an email. We are on a shared server, have we been blacklisted somehow?? Please advise.
Customer support service by UserEcho