Issue with bounce

Hi

One of our email recipients has suddenly ended up on the bounced list even though previously there have been no problems. I reset the status but it went back to bounced after the next message was sent.

Although I have configured an email address to receive bounce messages I have seen nothing come in.

I have read somewhere that the Mailpoet service may be responsible for setting the bounce status but cannot find a way to stop it for this address.

Can anybody help me please? I now have about 5 addresses which are set to bounced for no apparent reason.

Thanks

Ian