exchange 2019 ipblocklistprovider block e-mail even not in blocklist

[zhangchi2009]

hello guys ,

i'm facing a prblem on exchange 2019 CU3 .

i set the ipblocklistprovider as zen.spamhaus.org to prevent spam e-mails , but some e-mails from our costomer were blocked  .  i have checked the agent log ,and i can see the log which e-mails were blocked by zen.spamhaus.org .

1. i use test-ipblocklistprovider command to test the ipaddress of our customer , but the DNS lookup result from zen.spamhaus.org is "false"

2.  i try to add this ip address of our customer into ipallowlistentry , but no use , the e-mail still blocked .

does anyone can help on this ？

thank you very much .

[#2]

Hello @zhangchi2009 

I recommend that you review the https://practical365.com/exchange-server/add-ip-block-list-provider-exchange-server-2013-edge-transp...

Check also if there incorrect dns report.

[#3]

hello@Marco Antonio da Silva

thank you for your reply .

i think the anti-spam function is working now because i can see lots of spam e-mails were blocked .

the problem is some e-mails from our customer's were blocked but i want to add them into the whitelist . 

the way i tried to is to add the ip address into IpAllowListEntry , but no use , the e-mails still blocked .

so i'm looking for someone can help on this .

thank you very much .