Re: subbing envelope sender vs from:?

["David W. Tamkin" <dattier @ panix . com>]

Gerald Oskoboiny wrote:

> Upon receiving sub requests, some list management software
> attempts to sub the email address given in the From: header,
> others attempts to sub the envelope sender.

I hope that "attempts to sub" means "sends a confirmation request to."

 > Which behavior is correct, and why?

Can either be trusted any more?  It's tempting to answer, "Neither."