On 2023-05-09 at 16:17:57 UTC-0400 (Tue, 9 May 2023 20:17:57 +)
Gellner, Oliver via mailop
is rumored to have said:
I’d be surprised if there are many members on this list whose
systems do not penalize connections from IP addresses without a fully
confirmed reverse DNS entry one way or the
> I think we have to disagree here. The PTR naming is set via
> SendGrid. It doesn't NEED to be the same as the A record. This is
> for those MTA's that do forward/reverse matching, which isn't always
> successful.
>
> Yes, doing that for a IPv6 email address to satisfy Google, go ahead.
>
> But
> On 09.05.2023 at 20:46 Michael Peddemors via mailop wrote:
>
> But nothing wrong with sending an email from a PTR with a name, that doens't
> have the FQDN forward/reverse matched.
>
> As long as there is a URL associated with the domain name.
>
> eg. http://mileageplus.com (Redirect to UA site
Yeah.. always take stats with a grain of salt..
Besides, we know that spammers adopt these things faster than real
companies.. hehehe..
But the ones that don't have it (fcRdns) are often the emails that
people scream the most about missing.
oaky, going back to looking at the threat research
Heho,
hm, not sure. Looking at the 'email-security-scans.org' data, fcrdns is
at ~95.5% of senders. For comparison:
DKIM: ~55.2%
SPF & Valid: ~91.0%
TLS: ~96.0%
Greylisting (attempting to resend): ~97.4%
IPv4: ~97.9%
IPv6 (sending): 56.2%
IPv6 (sending+auth DNS+rec DNS): ~35.7%
So even though th
Hi Laura,
I think we have to disagree here. The PTR naming is set via SendGrid.
It doesn't NEED to be the same as the A record. This is for those MTA's
that do forward/reverse matching, which isn't always successful.
Yes, doing that for a IPv6 email address to satisfy Google, go ahead.
But
That’s a Sendgrid IP, they likely told UA to put in a DNS record, but UA never
did. ¯\_(ツ)_/¯ n
> On 9 May 2023, at 18:01, Stephen Frost via mailop wrote:
>
> Greetings,
>
> I'm getting some inbound email attempts that I believe are legitimate
> from United Airlines that are being rejected due
Greetings,
I'm getting some inbound email attempts that I believe are legitimate
from United Airlines that are being rejected due to:
May 9 12:55:38 tamriel postfix/smtpd[1221960]: warning: hostname
o1.email.smallbusiness.mileageplus.com does not resolve to address 50.31.61.242
Tracking this b
