Re: Check HELO

2020-09-16 Thread Matus UHLAR - fantomas
On Mon, 14 Sep 2020 15:08:57 +0200 Matus UHLAR - fantomas wrote: last time I checked, google, aol, yahoo SMTP servers used HELO strings that did not resolve back to those IPs. On 14.09.20 23:03, RW wrote: I just looked at few and they all have HELO matching the recorded rDNS. Are you basing

Re: Check HELO

2020-09-14 Thread John Hardin
On Mon, 14 Sep 2020, Bill Cole wrote: On 14 Sep 2020, at 11:22, John Hardin wrote: On Mon, 14 Sep 2020, Philipp Ewald wrote: Does anyone else checks the HELO/ELHO? I don't check for FCrDNS explicitly, but I do reject non-FQDN HELO strings (e.g. no dots present) from the Internet. That cat

Re: Check HELO

2020-09-14 Thread Bill Cole
On 14 Sep 2020, at 11:22, John Hardin wrote: On Mon, 14 Sep 2020, Philipp Ewald wrote: Does anyone else checks the HELO/ELHO? I don't check for FCrDNS explicitly, but I do reject non-FQDN HELO strings (e.g. no dots present) from the Internet. That catches a surprising percentage of garbage

Re: Check HELO

2020-09-14 Thread RW
On Mon, 14 Sep 2020 23:03:28 +0100 RW wrote: > > Are you basing that on PDS_NO_HELO_DNS? That rule FP'ed on any server > using IPv6 because it only checked for IPv4 rDNS. That should have been: only checks for an A record.

Re: Check HELO

2020-09-14 Thread RW
On Mon, 14 Sep 2020 15:08:57 +0200 Matus UHLAR - fantomas wrote: > last time I > checked, google, aol, yahoo SMTP servers used HELO strings that did > not resolve back to those IPs. I just looked at few and they all have HELO matching the recorded rDNS. Are you basing that on PDS_NO_HELO_DNS?

Re: Check HELO

2020-09-14 Thread Pedro David Marco
>On Monday, September 14, 2020, 05:23:13 PM GMT+2, John Hardin wrote: >I don't check for FCrDNS explicitly, but I do reject non-FQDN HELO strings  >(e.g. no dots present) from the Internet. That catches a surprising > percentage of garbage up front. +1 -Pedreter

Re: Check HELO

2020-09-14 Thread Matus UHLAR - fantomas
On Mon, 14 Sep 2020, Philipp Ewald wrote: Does anyone else checks the HELO/ELHO? On 14 Sep 2020, at 17:22, John Hardin wrote: I don't check for FCrDNS explicitly, but I do reject non-FQDN HELO strings (e.g. no dots present) from the Internet. That catches a surprising percentage of garbage u

Re: Check HELO

2020-09-14 Thread Niels Kobschätzki
On 14 Sep 2020, at 17:22, John Hardin wrote: On Mon, 14 Sep 2020, Philipp Ewald wrote: Does anyone else checks the HELO/ELHO? I don't check for FCrDNS explicitly, but I do reject non-FQDN HELO strings (e.g. no dots present) from the Internet. That catches a surprising percentage of garbage

Re: Check HELO

2020-09-14 Thread John Hardin
On Mon, 14 Sep 2020, Philipp Ewald wrote: Does anyone else checks the HELO/ELHO? I don't check for FCrDNS explicitly, but I do reject non-FQDN HELO strings (e.g. no dots present) from the Internet. That catches a surprising percentage of garbage up front. -- John Hardin KA7OHZ

Re: Check HELO

2020-09-14 Thread Philipp Ewald
that customer is apparently losing too much mail - last time I checked, google, aol, yahoo SMTP servers used HELO strings that did not resolve back Year - i thought there will be many false positive. what really matters is: 1. the PTR of connecting should be resolvable and the resulting host

Re: Check HELO

2020-09-14 Thread Matus UHLAR - fantomas
On 14.09.20 14:35, Philipp Ewald wrote: we have one customer the reported problems about HELO. We send the RFC821 HELO for only DOMAIN not FQDN. The customer scanning the helo and check the PTR and if the PTR don't match the HELO there is SPAM rating. this is forbidden by any SMTP RFCs issue