Q: iPhone cannot send mail through OS X server mail

I have just finished setting up an OS X Server (version 5.0 on Yosemite OS X).

I am able to send and receive mail on my mac all day long with no issues.

However, I can only receive mail on my iPhone, I cannot send mail.

I get errors stating I have an incorrect user name and password or the server does not support password authentication.

Has anyone run into this issue?

I truly appreciate your help, this is the last piece I cannot figure out.

I would also like to mention I am running a self signed cert. I don't know if this would make a difference.