Emails not send and receive from my website

Hello Daniel,

Am getting one problem,please help me.
Last one week onwards unable to send & receive emails from my website. php mail script is everything correct. please find below attached error image. am getting error is

Warning: mb_send_mail(): Multiple or malformed newlines found in additional_header in /home/estoor/public_html/system/library/mail.php on line 150

If i run same website backup in another server emails working perfectly. i am contacted hosting provider they will said "

We have investigated the issue in detail. While checking we could see that the issue was due to PHP version bug which is configured in the server . For resolving the reported issue you need to do the below instructions.
=============================
Upgrade your PHP version
or
Use php mail function instead of mbstring" like this .
what can i do please help me.its very very urgent for me. Please give me reply ASAP.

If your Hoster tells you, to upgrade PHP, you sure use no 'regular' hosted Server - Setup.
Because, if you would, your Hoster would have to do the PHP Version upgrade Job, and not you.

Also, the Hoster told you, to use the php mail function, instead of mbstring,
and additional_header is not an OC variable, it's clearly a PHP related value.

http://stackoverflow.com/questions/3094 ... ines-found
my Tip, use a decently set up Server, then, it will work.
Good Luck
Ernie