Ram: > I have a very busy postfix server that acts as a relay. It gets mails > from an application and then forwards the mails to the delivery servers > on local LAN > > The application can send mails at rate of? upto 600 mails per second > Postfix has been configured to accept mails all that quickly, but the > delivery is very poor until inflow stops. Only around 20-50 mails per s > Once the app completes the inflow, then the mails are cleared at a rate > of 1000 mails per second > > Why ? > > Is there a contention on the queue manager when the inflow is too quick ?
No, there is contention for the file system. If you disabled in_flow_delay, turn it back on, please. This allows the queue manager to push back, though it works only for clients that make few parallel connections. Otherwise, you need a faster disk. SSDs have become quite affordable, even the 'enterprise' ones that have some extra capacitors to prevent data corruption after power failure. Wietse