Sorry if this is a silly question, but I'm something of a Postfix (and
mail servers in general) newbie.
My Postfix server is all working fine, and is happily acting as a
relay for my local network.
However, I'm having problems when a user tries to send a single, large
message to a large number of recipients at different domains, relaying
via the Postfix server.
What happens is that Postfix receives the message from the sender,
queues it, then immediately connects to *all* of the destination
servers simultaneously and starts sending the message to them. This
completely saturates the upstream Internet link, so each destination
server sees a gradual trickle of data, and virtually all of them
time-out while receiving data.
Postfix then defers the whole message for x minutes, but when the x
minutes is up, it simply repeats the process, connecting to all the
remaining destinations at once, resulting in them (nearly) all timing
out.
Is there a way to limit the number of simultaneous outgoing
connections the server can make, so I can reduce this limit to 2 or 3,
and maybe have a fighting chance of the message actually being
delivered within a reasonable timescale?
Perhaps I'm thick, but I can only see options to set the maximum
number of connections per-domain - but the problem is a single message
going to multiple domains - I can't see any settings to change that.
Thanks in advance for any help.
