RE: [exim] Is there and logical reason to reject mail from: …

> The idea of using <> for a from address is to prevent mail
> loops. I have a thought on a solution for sender callout verification.

I always wonder why SMTP-RFC didn't do it differently. Always use normal sender/recipient information, but for 'bounce' messages use "ERROR"-command instead of DATA. And if on "ERROR" makes another "ERROR", don't send it to avoid loops. Besides this functionality "ERROR" would work like DATA. Too simple?