Increasingly, I've been receiving this error message when sending an email to a specific person. It's to my sister in law so no big issue to me, although the wife is making it my problem.
More of the message below - some changes for privacy;
Your message cannot be delivered to the following recipients:
Recipient address: <removed>@<removed>.karoo.co.uk
Reason: Rejection greeting returned by server.
Diagnostic code: smtp;550 Too many invalid recipients
Remote system: dns;mx.vip.karoo.kcom.com
Firstly, is this response coming from TelstraClear or from Karoo (the recipients ISP)? Obviously I would like to know whether I have to sort this out or she does.
Secondly, what does it actually mean? I've Googled the error and the reasons vary from too much spam (which I don't send and no I don't have trojans or viruses) to incorectly configured accounts. I don't get this specific message for anyone else (recently got rejected because a friend's mailbox was full) and as far as I can tell nobody is having any problems sending email to me.
What are your thoughts.