On 12 Dec 2005, at 15:50, John Levine wrote:

...

And BATV will never be widely deployed because it breaks every single system out there that keys off the return path. And there are a lot of these systems.

I keep hearing that, but other than a few ezmlm lists and the occasional tired fax gateway, I never run into them. Where are they?

I can't enumerate them all for you - I don't know them all. That's the point though - you can't know all the systems you may be breaking by changing the way your MAIL FROM works. Here's a few that I've told you about before: Whitelist/Blacklist entries Quarantine systems Anything based on .qmail files Some auto-forwarders Auto-responders Now you can potentially whitelist around these issues (to some extent), but while that works for geek mail systems it doesn't scale up very well. I know you (personally) whitelist around some problem systems in your implementation but can you expect Grandma to do that? Matt. ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________