On 2018-03-15 (09:01 MDT), Viktor Dukhovni <postfix-us...@dukhovni.org> wrote: > > Caching open TLS connections in the smtp(8) delivery agent for > reuse by scheduling repeated deliveries to the same delivery > agent runs into complex scheduling difficulties. The presence > of open connections don't, and should not IMHO alter scheduler > priority. Messages should still leave in approximately FIFO > order (subject to (n)qmgr's periodic preemption of messages that > split into many envelopes).
Isn't the issue a short-term one, where for example, a thousand mails hit the queue and 400 are for gmail.com and the desired behavior is to send those 400 in one connection whilst the others get queued up via a separate process? This could be done with a queue scheduler that pre-processes the queue when "a lot" of messages get queued for sending and then sorts them based on destination and the destinations that exceed some pre-defined threshold get shunted to a separate process. That seems like it is doable, if not simple. Heck, it could even only work if the messages were queued in order. Something along the lines of "I'm connected to big.example.com, is the next message to big.example.com? It is? OK, reuse this connection." This approach would do nothing about multi-destination emails, but I suspect that what is wanted by people in this thread doesn't involve multi-destination emails. -- <http://www.pvponline.com/comic/2004/01/14/wed-jan-14/>
