I'm getting the combination of these Postfix infos and I was wondering if I should be aware of something / someone.
30.4.2018, 10:08:33 info statistics: max cache size 1 at Apr 30 10:05:13
30.4.2018, 10:08:33 info statistics: max connection count 1 for (smtpd:87.243.7.183) at Apr 30 10:05:13
30.4.2018, 10:08:33 info statistics: max connection rate 1/60s for (smtpd:87.243.7.183) at Apr 30 10:05:13
30.4.2018, 10:05:13 info disconnect from unknown[87.243.7.183] helo=1 auth=0/1 quit=1 commands=2/3
30.4.2018, 10:05:13 info connect from unknown[87.243.7.183]
30.4.2018, 10:05:13 warning warning: hostname 183.7.243.87.static.primetelecom.ro does not resolve to address 87.243.7.183: Name or service not known
30.4.2018, 10:05:12 info PASS OLD [87.243.7.183]:64492
30.4.2018, 10:05:09 info addr 87.243.7.183 listed by domain zen.spamhaus.org as 127.0.0.4
30.4.2018, 10:05:09 info Look up 87.243.7.183 on whitelist, result 200 DUNNO
30.4.2018, 10:05:09 info CONNECT from [87.243.7.183]:64492 to [172.22.1.6]:25
30.4.2018, 09:56:57 info DISCONNECT [182.176.115.31]:54308
30.4.2018, 09:56:57 info DNSBL rank 14 for [182.176.115.31]:54308
30.4.2018, 09:56:55 info addr 182.176.115.31 listed by domain zen.spamhaus.org as 127.0.0.4
30.4.2018, 09:56:55 info addr 182.176.115.31 listed by domain zen.spamhaus.org as 127.0.0.11
30.4.2018, 09:56:54 info Look up 182.176.115.31 on whitelist, result 200 DUNNO
30.4.2018, 09:56:54 info CONNECT from [182.176.115.31]:54308 to [172.22.1.6]:25
30.4.2018, 09:51:40 info statistics: max cache size 1 at Apr 30 09:48:20
30.4.2018, 09:51:40 info statistics: max connection count 1 for (smtpd:87.243.7.183) at Apr 30 09:48:20
30.4.2018, 09:51:40 info statistics: max connection rate 1/60s for (smtpd:87.243.7.183) at Apr 30 09:48:20
30.4.2018, 09:50:00 info DISCONNECT [185.234.216.221]:59101
30.4.2018, 09:50:00 info DNSBL rank 9 for [185.234.216.221]:59101
30.4.2018, 09:50:00 info addr 185.234.216.221 listed by domain b.barracudacentral.org as 127.0.0.2
30.4.2018, 09:49:57 info addr 185.234.216.221 listed by domain zen.spamhaus.org as 127.0.0.4
30.4.2018, 09:49:57 info addr 185.234.216.221 listed by domain zen.spamhaus.org as 127.0.0.2
30.4.2018, 09:49:57 info PREGREET 11 after 0.03 from [185.234.216.221]:59101: EHLO User\r\n
30.4.2018, 09:49:56 info Look up 185.234.216.221 on whitelist, result 200 DUNNO
30.4.2018, 09:49:56 info CONNECT from [185.234.216.221]:59101 to [172.22.1.6]:25
30.4.2018, 09:48:20 info disconnect from unknown[87.243.7.183] helo=1 auth=0/1 quit=1 commands=2/3
30.4.2018, 09:48:20 info connect from unknown[87.243.7.183]
30.4.2018, 09:48:20 warning warning: hostname 183.7.243.87.static.primetelecom.ro does not resolve to address 87.243.7.183: Name or service not known
There are some parts like Look up 182.176.115.31 on whitelist, result 200 DUNNO
or PASS OLD [87.243.7.183]:64492
which I do not really understand.
What does PASS OLD or PASS NEW mean? I googled for it and read something about spam prevention, but for me this looks like spam, so why is postfix preventing the IP from it?