Here is the issue. We DO NOT want to use a 3rd party service, simply due to pricing.
We selected cs-cart in part of the built in newsletter features it has.
We have a VPS with 2gb of ram and a dedicated mysql server with 1GB , the site runs fine and rarely maxes out. with 500+ users.
Our main subscriber list is approx 150,000, we also have 3 others, dedicated for products, updates, and specials.
When we run our newsletter on the main list, it crashes our server because it sucks down 2 GB of ram, we have attempted to set the @ini_php to 1G, to limit the ram that script can use, however that is unsuccessful and it still drains our VPS of all the ram and our hosting company does an auto-reboot when it uses all the ram / maxes out. This can not be turned off on the hosting side.
What can we do to fix this issue? As stated, we dont want to pay or use any 3rd party service.