[eluser]oliviermarian[/eluser]
Basicly sending emails seems easy, but in another life I was owning a startup and some developpers created a full email program, with scheduling, bouncing email, clic tracking, test sending, text/html alternatives, opt-out, customisation regarding some emails (yahoo, ...) ...etc... As you say it's ever expending.
I've lost this program (the whole company in fact ;-( ... ) and now in my off time try to develop a guitar website with CI. I know I wont go again in the process of developing an email application.
php list seems quite fine.