[swinog] Email forwarding and backscatter, any idea how to solve?

Hello World!

I am working on renewing our ISP email solution. I'm focusing on minimizing any troubles while filtering spam etc. Eg, an email either arrives at the recipient or is rejected during SMTP handshake.

Unfortunately some customers do forward their email addresses to other addresses, this can be internal or external addresses and this can be multiple addresses.

In some cases it seems nearly impossible to me to prevent backscatter if you got email forwardings.

How do other ISP solve that problem? Just tell you customers you won't offer email forwarding any more?

Mit freundlichen Grüssen

Benoit Panizzon