25 Jun
2020
25 Jun
'20
3:30 p.m.
On Thu, Jun 25, 2020 at 2:27 PM jim stephens via cctalk <
cctalk at classiccmp.org> wrote:
The current message
"From" field contains the name of the original sender but with the
encoded address of the list as the email address
Unfortunately now there's no practical way for a mailing list to avoid
rewriting the From header to indicate that the messages are sent from the
list. If you don't do that, many (or most) mail servers (MTAs) will
silently drop the mail due to DKIM/SPF/DMARC failures.
If I send mail from foo at example.com to a classiccmp.org list, and then the
list sends it to all the subscribers _without_ rewriting the From header,
many (or most) receiving MTAs will find that the message fails origin
verification because classiccmp.org can't be validated as a legitimate SMTP
originator for email from example.com.
I'm surprised that use of an "X-Original-From" header or similar isn't
commonly used to work around this. Possibly people may think that it would
help spammers harvest email addresses, but it wouldn't make the harvesting
problem any worse than it was before From rewriting.
Some list software puts the entire original From address in the comment
part of the rewritten From header, rather than only the comment part of the
original.