I'm encountering some errors when I use localhost (no "from" email address).
Will I not encounter them when I upload?
Or how do I fix this in localhost so that I could also learn the problem behind it.
localhost would be difficult. you will have to setup SMTP and all that.
its not worth it if u r gonna use it as a full email system since u can't switch it on all the time.
Keep in mind that if you use localhost for a SMTP server you MUST (!!) have permission from your ISP. I've had a few emails come to my account stating that I've been sending out emails. Of course, I was just testing and fooling around.
Another way is setting the SMTP server and login information in the PHP.ini file, and it will use that SMTP server to send out mail from localhost. Don't remember how to do this, but it is possible.