Mark Martinec writes:
> > Yes, we have also seen it on many of our clients domains.

> Same here.
> Does anyone have operational experience with a scheme of labeling
> envelope sender addresses to recognize legitimate bounces to own mail,
> such as the BATV scheme (Bounce Address Tag Validation):
> What does such a scheme break? Do any mailing list management sw
> use envelope sender address for membership verification (instead of
> using author address in a From header field, or maybe in Sender)?

Embarrassingly, BATV breaks the ASF's ezmlm setup, which relies on the
MAIL FROM address to determine sender identity and list membership.
I think that's a bug in the ASF code.

Apparently it's otherwise quite useful, but you will need to maintain
a "whitelist" of BATV-excluded recipients...