Hi, in my current infrastructure we have several Relay systems which are responsible for transferering message thru different subnets to the internet.
At the moment our system sending aproximately ~30 000 E-mails per day, each E-mail is transfer thru few mail relay systems. Here You have some example: MTA CLIENT --- sent --- > RELAY01 --- sent ---> RELAY02 ---- sent ---> SMTP GATEWAY -----> INTERNET My first question: 1) what will happend with an E-mails if RELAY02 will not be available for a few hours ? In my understanding Postfix will put all E-mails to the deffered queue and it will store messages there till RELAY02 will not be available again. Is this correct ? 2) If Outage will take few hours (till one day). How much disk space do I need to prepare for all messages ? Is there any parameter in Postfix which limiting number of messages in the deffered queue ? What kind of message will be send to the client if deffered queue will be full ? How to properly plan disk space and queues for high loaded systems. Thanks in advance for all comments. With kind regards Zalezny
