Just hope to get some experience if someone occurs same situation as mine :
We're testing a ZCS (5.0.13 version Open Source Edition) on a Dell PE1950, 8G RAM, 2CPU (quad-core), external storage with Qlogic HBA (4Gbps).
When we test to send an email with 6K size to total 16000 local recipients, we found it almost spends 30 minutes when users can really see such email to enter their Inbox. and in the meantime, if someone sends emails from external site (e.g. @gmail.com ==> our site), it will be put into queue and be delivered after these 16000 delivery finished.
my questions are :
1. is there any system parameter which we can tune to speed up the delivery ?
2. if sender choose the "priority" and set it "Low" , what will happen? will system delays to this email to 16000 recipients , and will proceed other normal emails first ?
3. one email with 6K size to 16000 recipients in 30 minutes. does this number make sense? any knows how about in other email system?