How to handle special chars in email subject? - email

Question

I am using the Swiftmailer in my Symfony2 webapp.
// Subject and body dynamically come from database
$subject = "This is my subject with an apostroph ' in it.";
$bodytext = "Test text, also with an ' apostrophe in it.";
$message = \Swift_Message::newInstance()
->setSubject($subject)
->setFrom('me#mail.com')
->setTo('you#mail.com');
$message->setBody($bodytext);
$this->get('mailer')->send($message);
Now when there is a special char, e.g. the apostrophe (') in my subject, the email has a strange subject line in my email client:
This is my subject with an apostroph ' in it
Funny thing: The body text is displayed correctly, it's only the subject that's wrongly formatted.
Now how can I handle special chars like this - and even better, is there a function I can call before passing the subject that handles special chars in general?

Answer 1

Sorry, I know this is late but it might help anyone still having these similar issues.
I was having issues with apostrophe ' and ampersand & on SwiftMailer 6.2 so combining both htmlspecialchars_decode and html_entity_decode to convert the subject resolved it for me:
->setSubject(htmlspecialchars_decode(html_entity_decode($subject), ENT_QUOTES))
See https://www.php.net/manual/en/function.html-entity-decode.php and https://www.php.net/manual/en/function.htmlspecialchars-decode.php for further explanations.

Answer 2

Try to escape the subject with the htmlentities PHP function:
$subject = htmlentities("This is my subject with an apostroph ' in it.");