mail does not send to all domain names

[radd]

I use a very basic mail(); function that is not working on all domain names.
Such as, If the $to is set to "adam@agencemoon.com" everything works fine; but if I change it to: "adam@agence-moon.com" it stops sending emails.

Does it have something to do with the "-" in the domain name?

Even if the if(mail("adam@agence-moon.com",".... ...)) {} returns TRUE the email is not being received.
This is the phpinfo() page: http://www.agence-moon.fr/squelettes/test.php

[egami]

Do you have access to a shell ?

[radd]

I don't at this very moment, but I can ask if needed.
Why?

[egami]

if you can send mail from the shell.. ie..


telnet somedomain.com 25
HELO somethingelse.com
mail from: me@mydomain.com
rcpt to: this@address.com

and see what the error code says.

[radd]

I get a "telnet: command not found".
what are your commands doing? don't understand them...

[egami]

they are SMTP commands.

[radd]

ok, I can't use them...
do you have any other ideas?