Paul Smith writes:
If you're saying that Postfix can't handle that, so that it NEEDS to
have the timeout there set to 30 seconds or less, then all I can say
is Hmmm...
Wait.
As I said in my other mail, Postfix can handle it. But you might not be
happy with the resulting performance. The point is that Postfix won't
open more than 100 concurrent outgoing SMTP connections by default. In
the worst case, with 600-second DATA processing times, that means
Postfix can deliver only one message every six seconds.
In order to get decent performance, Postfix requires either
1. Shorter _average_ delivery time (that's average, not worst-case time).
or
2. The ability to open tens of thousands of concurrent SMTP connections.
I think the same is true for most MTAs.
Arnt