It's part of the config in main.cf You can specify "myhostname"
myhostname = host.domain.tld
Cheers, Curtis
On 6/30/20 4:55 PM, Istvan Prosinger wrote:
On 6/30/20 10:34 PM, Wietse Venema wrote:
Istvan Prosinger:
On 6/30/20 9:49 PM, Wietse Venema wrote:
Istvan Prosinger:
Hi, I hope this letter finds you well,
I have Postfix behind NAT, and added one failover IP to the main
router.
I wanted to "get by cheaply" by just doing something like
iptbales -t nat -I POSTROUTING -p tcp --dport 25 -j DNAT --to
<backup ip>
on the firewall machine.
So, all well, the only problem is that Postfix in this case has a
wrong HELO compared to the rDNS that I have defined
for the <backup IP>
It does throw a warning that the <backup IP> doesn't resolve to
it's hostname, but I'm not sure if I can define some
kind of helo_host_maps ;) to resolve this.
At this point, I wouldn't mind if someone pinpoints me to the
right direction.
Postfix does not compare the HELO command argument with forward or
reverse DNS information.
Antispam engines on the recipient side do
Thanks for clearing uo that 'It does throw a warning' is not
talking about Postfix.
Every MTA behind a NAT should send HELO to external hists using
the name of the outside NAT IP address. Use smtp_helo_name.
This is clear. But my problem is that I do the (pre)nating on the
firewall, I don't change any config for Postfix.
To simplify the question, it's - is it possible to have it use the
correct HELO depending on the outbound IP set on the firewall? I do
not change any relay maps, I just default it to anouther outbound IP
on the firewall.
best,
Istvan
