send email error

[eluser]Unknown[/eluser]
i can't send email...i'm working on domain provided by other server...

An Error Was Encountered

Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.

User-Agent: CodeIgniter
Date: Sat, 6 Aug 2011 04:18:46 -0500
From:
Return-Path:
To: [email protected]
Subject: =?iso-8859-1?Q?test?=
Reply-To: "ss@yahoo.com"
X-Sender: ss@yahoo.com
X-Mailer: CodeIgniter
X-Priority: 3 (Normal)
Message-ID: <4e3d06f6e1414@yahoo.com>
Mime-Version: 1.0


Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

[eluser]Unknown[/eluser]
[quote author="ss" date="1312641637"]i can't send email...i'm working on domain provided by other server...

An Error Was Encountered

Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.

User-Agent: CodeIgniter
Date: Sat, 6 Aug 2011 04:18:46 -0500
From:
Return-Path:
To: [email protected]
Subject: =?iso-8859-1?Q?test?=
Reply-To: "ss@yahoo.com"
X-Sender: ss@yahoo.com
X-Mailer: CodeIgniter
X-Priority: 3 (Normal)
Message-ID: <4e3d06f6e1414@yahoo.com>
Mime-Version: 1.0


Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

[/quote]