I have an email marketing app, so we have a great volume of mails to send and sometimes a great volume to the same MX. Depending the MX configuration we enter in a greylist and the server told us (in the log) to wait some minutes or second to continue sending messages to him. But postfix isn't smart enough to hold the messages to that domain that are in the queue.
So I wrote a log parser that gets the mail.log and in case it find any greylist warning it hold the messages to that domain. But I am not sure if this is the best/the right way to do it.
Do you have any other suggestions?
Yeah, I think I was not much clear in what I said. My postfix is with default configurations. What I have said is that when my server send a great volume to one MX this MX stop accepting my messages and tell my server that it is being greylisted and I should wait some minutes to continue sending messages to that MX.
I know that my server will try to send those messages again, but if ignore those graylist warnings and keep sending to that MX I got a bad deliverability.