eNewsletter not sending to all subscribers – page time out error

Hi there.

I noticed with my last to newsletters that not all my subscribers are listed. Been using the plugin for years and this is the first time this started happening now.

1. I create the newsletter.

2. Select the option to “Send out by Cron” and after a short while get a “page timeout” request.

When going back, I noticed that not all the subscribers numbers are different – couple hundred less.

Current PHP version: 5.6

max_execution_time 240 but increased now to 600

max_input_time -1

memory_limit 128m (Max)