Greylist delay problem

Hi,

a have Postgrey service installed (version: 1.3.0 (Build 2018032000)) on my I-MSCP server. I have more than 200 email users under several domains.

So I need this service, but in the days the customers realized that so many email delayed more than 10 hours and in some cases the mails arrive twice.

How can I check that this service working properly?

What config steps do I need to check?

Thank you!

Thank you.

I collected from my mail log one of the problematic sender log entries.
They use Microsoft Outlook mail service for own mail server.

I tried to hide the original domain names and sender / receiver addresses but hopefully it is still readable.

I attached the part of the log.

Thank you.

balilog.txt

Quote from f4Nm1Z9k2P

It seems that Microsoft is always using a new IP address, so mails won't pass greylisting. You have to whitelist Microsoft IPs.

Thank you!

Can I whitelist the whole domain in whitelist like this: *.outbound.protection.outlook.com ?

Or I have to collect all Microsoft's ip addresses and whitelist each ip?

Thank you!