I'm trying to send email through a Microsoft Exchange SMTP server using the Communicate Tool in EE admin. When I try to send an email, the browser spins for 5-10 seconds and then I get the following error message:
An Error Was Encountered Unable to send email at this time. 220 xxxxxxxxxxxxxxxxxxxx Microsoft ESMTP MAIL Service ready at Wed, 10 Dec 2014 07:52:35 -0600 hello: The following SMTP error was encountered: Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.
I know my settings in EE's Email Configuration are good. I've tested connecting to the Exchange server and sending email through both telnet and a PHP script and those both worked. And yet, ExpressionEngine won't send mail. What am I doing wrong?