Unable to configure newsletter

Hi,
i got the below mail from gmail team when i ran the test from wpmu plugin page of e-newsletter.

##################
You received this message because XXXX@gmail.com is listed as the recovery email for MAIL@XYZ.com. If MAIL@XYZ.com is not your Google Account, click here to disconnect from that account and stop receiving emails.
Hi Vijai,
Google just blocked someone from signing into your Google Account MAIL@XYZ.com from an app that may put your account at risk.
Less secure app
Wednesday, September 14, 2016 1:18 PM (GMT)
Don't recognize this activity?
If you didn't recently receive an error while trying to access a Google service, like Gmail, from a non-Google application, someone may have your password.

SECURE YOUR ACCOUNT

Google will continue to block sign-in attempts from this app because it has known security problems or is out of date. You can learn how to change your settings to allow access to less secure apps, but this may leave your account vulnerable.

Best,
The Google Accounts team
##############

I am using google apps for business, and i want the stuff to work with smtp. my mail id is like contact @xyz.com, and not contactxyz@gmail.com.