Verify Receivers not working

Mar 26, 2023
68
10
8
Hi there,

I have enabled (Configuration > Mail Proxy > Options > Verify Receivers > YES (550)) however, I still see logs like this.

Why did PMG even accept mail from real user noreply@goodexample.co.uk to non-exisitant user urkelu@kis5.com as kis5.com doesnt even have a MX.

Apr 14 11:45:38noreply@goodexample.co.ukurkelu@kis5.comqueued/deferred
Apr 14 11:45:38 pmg2 postfix/qmgr[1049185]: C00FF180446: from=<noreply@googexample.co.uk>, size=11664, nrcpt=1 (queue active)
Apr 14 11:45:38 pmg2 postfix/smtp[1052515]: C00FF180446: to=<urkelu@kis5.com>, relay=none, delay=128715, delays=128715/0/0.09/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error
 
Update - that did not work.

Setting the;

Configuration > Mail Proxy > Options > Before Queue Filtering (Yes)
Configuration > Mail Proxy > Options > Verify Receivers > YES (550)

I still see lots of queued/deferred for:

  1. unable to verify address (in reply to MAIL FROM command)
  2. (Host or domain name not found. Name service error for name=brainline.com.co type=MX: Host not found, try again)
 
Last edited:
can you post a bigger part of the log where this occurs ?
 
can you post a bigger part of the log where this occurs ?
Hi, is there a preferred method to provide logs without them being public?
I've tried to hide sensitive info here:

Code:
Apr 17 12:13:13 pmg2 postfix/smtpd[1922082]: 30CB6181CA4: client=localhost.localdomain[127.0.0.1], orig_client=my.plesk.server[1.2.3.4]

Apr 17 12:13:13 pmg2 postfix/cleanup[1922083]: 30CB6181CA4: message-id=<aec06bdd8c34e4d495b31ae96cbf645a@sendingdomain.com>

Apr 17 12:13:13 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)

Apr 17 12:13:13 pmg2 pmg-smtp-filter[1919705]: 181CA3643D29C89082C: accept mail to <receiver@receiverdomain.com> (30CB6181CA4) (rule: default-accept)

Apr 17 12:13:16 pmg2 postfix/smtp[1922084]: 30CB6181CA4: host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)

Apr 17 12:13:20 pmg2 postfix/smtp[1922084]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=7.4, delays=0.05/0/7/0.31, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))

Apr 17 12:22:48 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)

Apr 17 12:22:52 pmg2 postfix/smtp[1924051]: 30CB6181CA4: host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)

Apr 17 12:22:55 pmg2 postfix/smtp[1924051]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=582, delays=576/0.08/6.2/0.29, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))

Apr 17 12:32:49 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)

Apr 17 12:32:51 pmg2 postfix/smtp[1925997]: 30CB6181CA4: host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)

Apr 17 12:32:54 pmg2 postfix/smtp[1925997]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=1181, delays=1176/0.06/5/0.29, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))

Apr 17 12:52:49 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)

Apr 17 12:52:52 pmg2 postfix/smtp[1930078]: 30CB6181CA4: host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)

Apr 17 12:52:55 pmg2 postfix/smtp[1930078]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=2382, delays=2376/0.11/5.4/0.31, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))
 
if i interpret these logs correctly the receiving server rejects the mail only after the MAIL FROM command, but according to the postfix docs: https://www.postfix.org/ADDRESS_VERIFICATION_README.html it needs to be in response to the RCPT TO command
(since that is what it checks)

also, are you sure you replaced the mails correctly? it seems that the receiver server does not reject the target email address, but the source (the 'sendingdomain.com' )
 

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