[BlueOnyx:26393] Re: The Postfix learning curve continues

[Michael Stauber]

Hi Chad,

> The relay error comes in this section:
> 
> 
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: generic_checks: 
> name=permit_mynetworks status=0
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: generic_checks: 
> name=reject_unauth_destination
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: 
> reject_unauth_destination: emailalert at domain.com
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: 
> permit_auth_destination: emailalert at domain.com
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: ctable_locate: 
> leave existing entry key chad at bersche.com?emailalert at domain.com
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: NOQUEUE: reject: 
> RCPT from backup.bersche.com[172.18.172.106]: 554 5.7.1 
> <emailalert at domain.com>: Relay access denied; from=<chad at bersche.com> 
> to=<emailalert at domain.com> proto=ESMTP helo=<localhost>
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: generic_checks: 
> name=reject_unauth_destination status=2
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: >>> END Recipient 
> address RESTRICTIONS <<<
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: > 
> backup.bersche.com[172.18.172.106]: 554 5.7.1 <emailalert at domain.com>: 
> Relay access denied
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: watchdog_pat: 
> 0x558e6487faa0
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: 
> vstream_fflush_some: fd 10 flush 53
> Jul 31 14:36:33 mail postfix/submission/smtpd[645290]: smtp_get: EOF

Yeah, I was looking at this on Monday when my internet problems started.

 From what I an see there it's not DNS. Your server is rejecting the 
relay for the recipient domain "emc.com" with the message "Relay access 
denied."

Whitelisting the sending IP in "Relay Email From Hosts/Domains/IP 
Addresses" in the GUI does the trick for Sendmail, but Postfix is more 
picky it seems.

So this is really something that we need to put into "mynetworks" instead.

Change your "mynetworks" line in /etc/postfix/main.cf to something like 
this if you want to allow the whole 192.168.0.0/16 network to be able to 
relay through it:

mynetworks = 127.0.0.0/8 [::1]/128 192.168.0.0/16

Then restart Postfix and see if that helps:

systemctl restart postfix

-- 
With best regards

Michael Stauber