Where to put an email function

[eluser]sophistry[/eluser]
depending how you want to set it up you could also make a master controller (a front-controller) by subclassing all of your controllers to one master controller then put the snippet functions in there.

also, a helper is a good place for code that simply "wraps" other code. read up on helper in the guide.

if you want to still build your own separate library that talks to CI the user guide referenced above has info on that too. search on get_instance.