==== Required information ====
- iRedMail version (check /etc/iredmail-release):  0.9.3
- Linux/BSD distribution name and version: Deb 7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? Yes
- Related log if you're reporting an issue:
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I'm using iRedAPD-1.7.0

I have noticed a few times when going through my logs that some emails are not getting through to the reciepant.

I have greylisting enabled.

When the initial first attempt is made to deliver, iRedmail issues a "Recipient address rejected: Intended policy rejection, please try again later". The incoming SMTP host's IP address is added to the greylisting table. Now when the incoming SMTP host tries again and everything matches up the email is passed along to the email account.

What I have noticed is that some servers offload the retry to another SMTP in their network to retry to deliver and thus the IP address is different and when that happens some servers then offload the retry to yet another SMTP in their network to retry to deliver and thus the IP address is different again and so on and the email never gets delivered.

Is the only way around this to do a whitelist?