[Mimedefang] Sender 'callback' Checks?

[Simon Standley]

Jonas Eckerman wrote:

> If you are talking about verifying sender addresses by doing SMTP 
> callouts to MX servers, you should know that this may get your 
> server blacklisted since it's considered abusive by many and 
> because it may well make your server connect to spam traps.

That's exactly what I'm talking about. Essentially 'md_check_against_smtp_server' with some additional caching.

Re- 'abuse' - that's an interesting take on things that I'd not taken into account. I can't imagine how anyone would take offence at this, or even how they would deduce motivation behind what we're doing, given the many other situations in which an SMTP session could be dropped after RCPT. But that's not the point - if people *do* take offence, its something to consider. Please can you point me at and examples of blacklists, etc, that specifically categorise this type of activity as 'abuse', so I can understand their PoV more completely?

Thanks!

Si.