I am trying to send emails through sendgrid in Zend application. I copy the php code from the sendgrid documentation (smtapi class and swift). I create a template with places that should be substituted with %variable%. Now I create headers for sendgrid as defined here: http://docs.sendgrid.com/documentation/api/smtp-api/developers-guide/ In result I get something looking like this: { "to": ["[email protected]", "[email protected]", "[email protected]", "[email protected]", "[email protected]"], "sub": {"%firstname%": ["Benny", "Chaim", "Ephraim", "Yehuda", "will"]}, "section": {"%postername%": "Rabbi Yitzchak Lieblich", "%postermail%": "[email protected]", "%categoryname%": "General", "%threadname%": "Completely new thread", "%post%": "This thread is to inform you about something very important", "%threadurl%": "http:\/\/hb.local\/forums\/general\/thread\/143", "%replyto%": "http:\/\/hb.local\/forums\/general\/thread\/143", "%unsubscribeurl%": "http:\/\/hb.local\/forums\/settings\/", "%subscribeurl%": "http:\/\/hb.local\/forums\/subscribe-thread\/id\/143\/token\/1b20eb7799829e22ba2d48ca0867d3ce"} } Now while all data defined in "sub" changes I cannot make section work. In the final email I still got %postername%. When I move this data to sub and repeat them for each email everything is working fine. Has anyone a clue what I am doing wrong? Docs for section are here: http://docs.sendgrid.com/documentation/api/smtp-api/developers-guide/section-tags/