Exim Batch sending
As a server administrator, I would like to see the possibility to configure some kind of batch sending for outgoing emails.
User is sending 1 email to 200 recipients, currently what cpanel does, is random batching, this means it might split up the recipients into 3-5 batches, some batching containing 40 emails others containing 100, and some 30 e.g.
I would like to see following feature:
1: If user send email to x recipients, start a rate limit.
2: Exim will say, okay, I need to send to 200 recipients, lets batch it, to 20 recipients per batch.
3: Every minute exim will send those 20 emails.
So instead of sending 100 emails at same second (or few seconds), we rate limit to 20 emails per minute (or whatever we define).
This would help improving delivery, since it will look less spammy for email hosts, that they receive 100 emails within 3-4 seconds.
Another way of doing it, could be, you queue up all emails send by the user, and rate limit them to sending 1 email every 2 or 3 seconds. (This is what many email providers do).
Please make this feature, so we don't need to use external mail providers for getting this functionality.