Simple Email Collection

I’m really amazed there are no plug-ins that make it easy to add a 1 box email form to collect addresses for newsletters.

Is this because building/integrating one is just too simple on its own? I’d really like to know why this is or at least hear other peoples opinions. I’d consider myself a novice in that area.

Maybe I’m making things unnecessarily difficult. What do you guys use to create these forms? Do you modify other forms like Fast & Easy Contact Form for example?

I’m looking into how to just write the PHP now but apparently there are some big points (for me) to take care of:

* the code itself & regular expressions for validation
* sanitize user input (whatever that means)
* double opt-in process

Appreciate any help or if I’m missing something let me know.