TOL publishes a list of their mailservers and also has them listed at DNSWL.
The list auf these ~20 IPs probably is in many configs somewhere. And/or a
F.e. when TOL gets listed on Spamcop or others again.
Von: owner-postfix-us...@postfix.org Im
Auftrag von Henry R
Gesendet: Samstag, 10. Dezember 2022 04:47
Betreff: google's receiving policies
t-online has no SPF & DMARC & DKIM settings. but google try to maintain a
reliable sender IP list for them.
if you forward a message which is original from t-online to gmail, if you don't
have SRS enabled for this forwarding, gmail will just reject it.
as far as I know, many ISP level forwardings have NO SRS setup, including
Mail.ru, Freenet.de, and even Outlook.
since there is no spf, no dkim for t-online, how google know it's coming from a
valid IP? the only reason I can image is that google help maintain that a ip
list for t-online itself.
how do you think of this?
Thanks & regards.