Minor update of DJ-Classifieds was just released. This update fixes the issue that appeared along with Joomla 3.5.1 and emails.
Joomla 3.5.1 brings modifications in mailer functionality, it's mostly connected to TLS change in PHPMailer 5.2.10 but there are also some changes in functions , like addReplyTo() . Previoustly array was accepted as a argument but now email and namy must be send in different arguments. Version 3.4.5 of DJ-Classifieds fixes that issues.
You'll also find other minor fixes for DJ-Classifieds and Subscription Plans App.
Check the changelog for this version to see the complete list of changes.