11 Nov
2018
11 Nov
'18
3:23 a.m.
This is easily circumvented by mailer software like this one.
It does NOT send mails as coming from the user. It just changes the name:
If I send a mail to this list, I send it from "Marius <marius(a)yo2loj.ro>"
The mailing list SW will send it from "Marius via 44Net
<44net(a)mailman.ampr.org>"
Even if that "via 44Net" would not be there, it still is a mailer's
address.
The same applies if the sender would be "marius(a)yo2loj.ro
<44net(a)mailman.ampr.org>"
It would APPEAR it was sent from me, but the actual address is mailman's
address.
On the other hand, mail servers are right, one can not send mail to them
using their own domain, unless allowed by some trusted source (DNS SFP
reccord or similar in the mail host's record) authorizing the external
host to send mail in its name.
And it is not only yahoo doing this, most mail servers reject such
mails. They also reject unknown sender hosts (without RDNS entries),
invalid HELLO headers and others.
Google is the exception, classifying it as spam instead of just
rejecting it with a 554 error.
IMHO this whole thing is actually in place for years, and a non-issue.
As long as a mail server is correctly configured, everything works as
expected.
Marius, YO2LOJ
On Sat, 10 Nov 2018 at 07:32, Neil Johnson
<neil.johnson(a)erudicon.com>
wrote:
(...)
Unfortunately this breaks mailing list software like mailman (used for this
list) which tries to make e-mail from the list appear as if it is coming
from the original sender.
The changes that are required to fix the issue change the functionality of
the list software in ways users may not like.