I have a PHPList 2.11.7 development version, installed and running on AWS EC2, I made a micro instance, and uploaded an image that contains CentOS 5.8 32-bit version since supposedly PHPList isn't working perfectly with newer PHP versions (5.3 and above). I think the development version is suffering from regressions or maybe the old Apache version (2.2) is buggy or sluggish, I am not so sure.
Currently it is sending about 2k/hr. The CPU load is pretty low, almost at 20% and more than 50% of the RAM is free. I can't find any kind of bottleneck. The MySQL database is running smoothly on EC2 and it doesn't seem to be the bottleneck.
I am thinking that if I used the production version of PHPList (currently 2.10.19) while using SES via SMTP it will be much better, however after some research it appears that this version doesn't support TLS which is required for SES in case of using SMTP.
Another idea that I am thinking about is installing postfix to use it as a relay between PHPList and SES.
Yet another idea in my mind is using GNU Mailman instead of PHPList to send mails to SES via SMTP.
So is there a way to increase the performance to 3k/hr or even more? My SES quota is 100k/day, 28/sec.
I am stuck and confused, been trying to find a solution for days, I appreciate any suggestion or comment.