This release of PHPMailer (v5.0.0) sets a new milestone in the development cycle of PHPMailer. First, class.phpmailer.php has a small footprint (65.7 Kb), while class.smtp.php is even smaller than before (at only 25.0 Kb).
We have maintained all functionality and added Exception handling unique to PHP 5/6.
There is only one function that has been removed: that is getFile(). The reason for this is that getFile() became a wrapper for the PHP function 'file_get_contents()' and nothing more. Rather than burden the class with a function already available in PHP, we decided to remove it.
Our new Exception handling provides your own scripts far more power than ever.
We have also enhanced the "packaging" of PHPMailer with an entirely new set of examples. Included are both basic and advanced examples showing how you can take advantage of PHP Exception handling to improve your own scripts.
A few things to note about PHPMailer:

- the use of $mail->AltBody is completely optional. If not used, PHPMailer will use the HTML text with htmlentities().
  We also highly recommend using HTML2Text authored by Jon Abernathy. The class description and download can be viewed at: http://www.chuggnutt.com/html2text.php.
- there is no specific code to define image or attachment types ... that is handled automatically by PHPMailer when it parses the images

A note to users that want to use SMTP with PHPMailer. The most common problems are:

- wrong port ... most ISP (Internet Service Providers) will not allow relaying through their servers. If that's the case with your ISP, try using port 26.
- wrong authentication information (username and/or password) ... don't forget that many servers require the account name to be in the format of the full email address.
- ... if these tips do not get your SMTP settings working, we have a debug mode for helping you determine the problem. Insert this after $mail->IsSMTP();
  $mail->SMTPDebug = 2; note that a setting of 2 will display all errors and messages generated by the SMTP server

Our examples all use an HTML file in the /examples folder. To see what the email SHOULD look like in your HTML compatible email viewer: click here
From the PHPMailer team:
Author: Andy Prevost (codeworxtech) codeworxtech@users.sourceforge.net (and Project Administrator)
Author: Marcus Bointon (coolbru) coolbru@users.sourceforge.net