Mail sending issue, asp.net

Im having issue with mail sending In web.config file

开发者_开发百科

<mailSettings>
    <smtp from="xxxx@companyname.com">
    <network host="mail.authsmtp.com" port="25" userName="xxxx@companyname.com" password="****" defaultCredentials="false"/>
            </smtp>
        </mailSettings>
</system.net>

I used mail sending code to send mail

but im getting exception as, The server response was: 5.0.0 Your email system must authenticate before sending mail:XM_ERR:xxx.xxx.xxx.xxx(my ip addr)

Please let me know how to solve this issue.

Thank you

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Do you want to use credentials from web.config file?

If yes, than change defaultSettings to true.

If not, than you must supply valid credentials in code.