This question may not just be a CodeIgniter related question, but since I am working with CodeIgniter, the context of the question was how I determined where to post.
CodeIgniter has an email class, and when using it, it defaults to 'mail' as the protocol. Other options are 'sendmail' and 'stmp'. In my adventures with CodeIgniter, I've never had to configure this option, but on my most recent project, sending email was doing VERY buggy things. Through trial and error, I found that changing the protocol to sendmail was all that was needed to be done to fix everything. What's really weird is that 'mail' would send standard email most of the time, but would never send html email. Also, mail delivery was totally random, and Google wouldn't accept the mail no matter what I did. I was even getting a confirmation (success) message when I used 'mail', so I never thought to change the protocol until a lot of time went by. I initially thought that there was some other problem, like with my controller, or the email content view. Is there a way to look at PHP info and know right away if the server uses mail vs. sendmail ??? I don't want to have to waste so much time with this again!