CPI Mail adapter Error

Hi Team

I want to trigger email in Exception sub process

My client is using office365.

In mail Receiver adapter if I put address as smtp.office365.com:587 and even I use correct user credential I am getting below error.

javax.mail.AuthenticationFailedException: 535 5.7.3 Authentication unsuccessful [SY2PR01CA0005.ausprd01.prod.outlook.com]

If I use Gmail server details Address: smtp.gmail.com:587 and Gmail credential it is working

Strange thing ,If I use my outlook id (office 365) in CC , then also it send email successfully.

But in prod iflow we can not use trick to use Gmai server address and keep official Ids in Cc.

does anyone face this same issue?

Thanks

Harsha