Make your PHP sessions last longer
It’s pretty simple.
ini_set('session.gc_maxlifetime',n);
where n is the number of seconds before the session times out.
Add image embedding to PHP List
Change your phplist to automatically embed all images in the emails, so that users don’t have to deal with their email clients asking them to download the images.
I will consolidate the solution and post it here soon, for now see the above post.