I am attaching some pictures that show the options that I have in settings.
The first picture actually shows the settings of directadmin under »User Level
I don't think the name of your domain is
domain.com (I know who owns that domain; they paid a lot of money for it, and they don't run DirectAdmin). Please see
this page (homepage.ntlworld.com) for good reasons why you shouldn't obscure your DNS data when asking for help.
But note carefully the checkbox is not checked. This means DirectAdmin isn't attempting delivery on your server, but rather for an mx record for domain.com. Since domain.com isn't hosted on your server, if your DNS is set properly it's attempting to deliver the email to a server at domain.com, and if they have an email address the same as you're they're getting the email. If not, the email is being bounced back to your server, check your exim queue.
The second picture shows the information of the domain (one domain) is stored on the server
So why do not Send Mail? Even from the server and stored on the server accounts?
The second image you've attached shows that email for iphoneil.net is hosted at a Google ac****, but because you do have the checkbox checked any email originating on the server is delivered not to Google, but to your local mail, which you're likely not checking, and you may not even have a mailbox set up for that email address on your server.
As I wrote above in this reply, if these are really your settings the email is being sent to
[email protected], if there really is such an acount there. EIG, a major registrar, owns the domain name domain.com.
If you're going to use example domains you should use the domains example.com, example.net, and example.org, as they have been designated specficially for the purpose. But if you still need help after reading this, and if my reply to the second image doesn't help you, then when you write again include links only to real images showing your real information, so we may actually help you by doing lookups instead of guessing.
If you don't want to do that, then hopefully someone else can help you, because I've done all the guessing I can do. You've already got my best guesses.
Jeff