Postgrey blocks Outlook and most of the legit mail servers

We encountered a lot of issues with postgrey that it seems to greylist or even totally block some legit websites and even outlook so the solution is to decrease the delay into 1. Open /etc/postgrey and set this line into this

The delay that is set to 1 will lessen that delay that a mail server can knock again to your server and be allowed again to send. usually spammers don’t try bothering to retry sending at all but just to make sure use spamassassin.

With the issues that some legit mail servers are blocked sending emails to your server you can use this commonly updated postgrey_Whitelist_clients that contains the whitelisting for all outlook mail servers. just create /etc/postgrey/whitelist_clients.local containing the following configuration of this file

https://github.com/schweikert/postgrey/blob/master/postgrey_whitelist_clients