PHPMailer BUG : Splits the subject line in the middle of a multi-byte character

PHPMailer is one of my favorite library for sending email since long. I though it is really mature library and still I believe it. Nowadays its getting more & more mature.  I was using PHPMailer v1.73.

Last week I week, I have seen major bug in my application. It makes junk char/mojibake in subject line. I use all content in utf-8. I set all settings to make email completely utf-8. Then I try to read code of my project 2-3 times but it has not problem at all. Then I moved to Google to search solution for the problem. I found following links.

#2957 ([PATCH] Long utf-8 encoded subject fails (phpmailer bug)) – symfony – Trac

Then I realized that problem is in PHPMailer library. Following is the actual problem. If a subject line contains non US ASCII characters and the encoding is set to UTF-8, phpMailer occasionally splits the subject line in the middle of a multi-byte character, causing the encoded representation to appear in the email client. Specially problem appears when email subject contains multi-byte char & length is more than 20 char. You can usually find problem around or after 20th char.

#2957: encoding.patch – symfony – Trac

The above link has also given solution to the problem. But before adopting patch,I visited the PHPMailer site ( I found PHPMailer 2.2.1 is already released on July 20 2008. Then I downloaded the latest version & checked its code, same patch is found in latest release. So I upgraded to PHPMailer 2.2.1.