There's also a good chance it's one of the domains listed here: https://www.spamresource.com/2024/07/altice-usa-suddenlink-optonline.html
But, like Suresh said, just look for SMTP handoff to an openwave.ai server in the outbound MTA logs, if you're able to. If not, take the list and write a script to log the MX for every domain for every recipient and see which ones MX to openwave.ai Cheers, Al Iverson On Sat, Oct 11, 2025 at 10:11 AM Suresh Ramasubramanian via mailop <[email protected]> wrote: > > Just check your outbound for mail delivery to *.openwave.ai? > > --srs > ________________________________ > From: mailop <[email protected]> on behalf of Ken Robinson via mailop > <[email protected]> > Sent: Saturday, October 11, 2025 6:05:01 PM > To: mailop <[email protected]> > Subject: Re: [mailop] Getting a bounce from one of my mailing lists & I can't > determine where it's coming from > > I think I figured out why the original bounced -- there are return > characters, "\n" in the Subject line. I looked at the mail logs on my server > and saw that. > > The bounce message came from the server at > altprdrgo002.altice.prod.cloud.openwave.ai, but that still doesn't tell me > much. > > Thanks, > Ken > > On Sat, Oct 11, 2025 at 7:42 AM Benny Pedersen via mailop <[email protected]> > wrote: > > Rainer Daeschler via mailop skrev den 2025-10-11 10:41: > > Hi Ken, > > > >> Please reply to <Postmaster@ {mx.internal}> > >> if you feel this message to be in error. > >> > >> The original message has been removed from the bounce message. > >> > >> Reporting-MTA: dns; altprdfep009. {mx.internal} > >> Arrival-Date: Thu, 9 Oct 2025 08:02:03 -0400 > >> Received-From-MTA: dns; altprdrgi011.altice.prod.cloud.openwave.ai > >> [1] ( {10.33.66.227}) > >> Content-Transfer-Encoding: 7bit > >> … > >> Diagnostic-Code: smtp; 550 5.7.1 Spam detected by content scanner. > >> Message rejected > > {mx.internal} = none existent domain > > {10.33.66.227} = private IP address, not the IP from > > altprdrgi011.altice.prod.cloud.openwave.ai. > > > > No wonder it's considered spam. > > :-) > > postfix can reject rfc 1918 mx hosts via cidr maps > > # cat main.cf > > smtpd_sender_restrictions = ... check_sender_mx_access > cidr:/etc/postfix/rfc1918.cidr > > # cat rfc1918.cidr > > Here are some other things you can do with check_*_mx_access (this is > a "cidr:" map type): > > 0.0.0.0/8 REJECT Domain MX in broadcast network > 10.0.0.0/8 REJECT Domain MX in RFC 1918 private network > 127.0.0.0/8 REJECT Domain MX in loopback network > 169.254.0.0/16 REJECT Domain MX in link local network > 172.16.0.0/12 REJECT Domain MX in RFC 1918 private network > 192.0.2.0/24 REJECT Domain MX in TEST-NET network > 192.168.0/16 REJECT Domain MX in RFC 1918 private network > 224.0.0.0/4 REJECT Domain MX in class D multicast network > 240.0.0.0/5 REJECT Domain MX in class E reserved network > 248.0.0.0/5 REJECT Domain MX in reserved network > > pretty safe if remote is ipv6 :) > > in that case add ipv6 to cidr map > _______________________________________________ > mailop mailing list > [email protected] > https://list.mailop.org/listinfo/mailop > > _______________________________________________ > mailop mailing list > [email protected] > https://list.mailop.org/listinfo/mailop -- Al Iverson // 312-725-0130 // Chicago http://www.spamresource.com // Deliverability http://www.aliverson.com // All about me https://xnnd.com/calendar // Book my calendar _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
