On Fri, 08 Jul 2005 14:14:46 +0100 (13:14 UTC) David Woodhouse wrote:
However, some seem to have stated that forwarding was somehow 'wrong'
for reasons _other_ than the limitations of SPF. That it was a bad thing
even _before_ SPF was invented. It was _that_ which I do not understand,
and was asking someone to explain.
Long before SPF, back in the days of sendmail 8.8.8, we
started rejecting emails which _could_ have been forgeries
from a number of domains. With more than 20 email addresses
on the original "millions CD" and with over 60 thousand
spamtrap email addresses, it wasn't hard to instrument and
determine many domains which were being often forged.
That list of oft-forged domains continues to grow,
totally separate from any SPF-related activities.
It also wasn't hard to start refusing email from those
oft-forged domains which arrived from IPs for which rDNS
and rechecking of the forward DNS for that name did not
correctly point to the domain's IP space. Over the years,
it has been necessary to (very) occasionally white list a
sender. We currently have 27 entries in our white list
caused by _potentially_ forged email sources, with
precisely one of those entries due to a person who uses
traditional, non-trusted.forwarders-listed forwarding.
Your mail systems may handle a lot more than ours (we
are under a quarter million most hours), but this does not
seem to be an insurmountable burden for most non-immense
email handlers. Certainly the burden of white-listing a
sender due to their desire to use their alma mater or
professional affiliation in their preferred public email
address is not something over which I'd lose any sleep.
If it ever became a weekly event, a little script work
would take care of the additional workload.
Back to mostly-lurking mode for me,
Len