On 2022-04-11 17:00, Matus UHLAR - fantomas wrote:
On 11.04.22 15:38, Richard Rasker wrote:
I've been using Postfix for many years without significant problems.
However, due to a forced change in ISP, I can no longer have a
correct PTR record pointing to mail.linetec.nl, causing a lot of
ISP's to reject e-mail from my server.
Reverse DNS for my IP address now points to the ISP's generic name
77-172-184-9.fixed.kpn.net
Could I solve this by setting smtp_helo_name in main.cf to
77-172-184-9.fixed.kpn.net ? Or is this a bad idea?
Op 11-04-22 om 16:17 schreef Matus UHLAR - fantomas:
this will not help your problem. many ISPs will reject not because
helo name but because of your reverse DNS format.
ask your ISP to change reverse DNS for your IP to mail.linetec.nl
when possible.
if not possible, you'll need external smtp server, or different ISP.
On 11.04.22 16:52, Richard Rasker wrote:
Unfortunately, my new ISP says they can only do that for business
accounts, which would cost me several dozen euros extra per month.
yes, quite common. One ISP even told me they only provide static IPs
to business accounts... Changing ISP is your possibility to check -
you have to find out which is cheaper or more reliable.
relayhost = smtp.xs4all.nl
#Enable Authentication
smtp_sasl_auth_enable = yes
#Set Username and Password
smtp_sasl_password_maps = static:Chosen-Username:Chosen-Password
smtp_sasl_security_options = noanonymous
#Enable TLS Encryption
smtp_tls_security_level = encrypt
header_size_limit = 4096000
#Enable CA Certificates
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt
When restarting Postfix, no mail at all seems to be getting through
any more -- and how should this solve the reverse DNS problem? Because
smtp.xs4all.nl has IP address 195.121.65.191, but this IP address
again does not point back to smtp.xs4all.nl ...
https://multirbl.valli.org/lookup/195.121.65.191.html
seems dynamic ip, hence there ptr is correct !
did you provide another ip here ?
as I explained in different thread, this completely does not matter.
if no mail is getting through, there is different problem.
is there anything related to SMTP in your logs?
Perhaps you need to use different port (587 or 465 with
smtp_tls_wrappermode) with their smtp server. port 25 is often
blocked.
setup postfix to use gmail as smtp client with sasl auth is possible if
all else fails
replace if needed gmail with another host you control
