SMTP - Office 365

I've configured the SMTP options for Office 365 but I'm getting this message when I'm trying to send a reply to one ticket. Our Kayako Fusion version is 4.65

Uncaught Exception
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#0 .\__swift\thirdparty\SwiftMailer\classes\SwiftMailer\Transport\StreamBuffer.php(64): SwiftMailer_Transport_StreamBuffer->_establishSocketConnection()
#1...

SMTP - Office 365