Error when sending private message on Elgg 2.3.2

Hi everyone.  I am having an error on a new installation of Elgg 2.3.2. When I try to send a private message, 

The php error is as follows:

Fatal error: Call to undefined function Zend\Mail\Header\iconv_mime_decode() in /home/rnetw/public_html/vendor/zendframework/zend-mail/src/Header/HeaderWrap.php on line 106

Any form of assistance on this is appreciated. Thanks.