By default WordPress Uses PHP Mail function to send generated emails, in some cases where php mail function is not adequate to send enough mails or its ip address are not white listed to reach users inbox , only hope is to use an External SMTP server. As far GMAIL is the most popular mail service to offer FREE SMTP its a good idea to use Gmail instead. To start with we need to enable SMTP feature to the core. The simplest and easiest method is to install WP Mail SMTP. Once activated, goto Settings -> Email Fill out necessary details and ensure check Use SSL while using Port 465, and opt SMTP Authentication. Supply SMTP Host as : smtp.gmail.com and , Port Number as : 465. and Save settings The same can be used with your Google App account , here is the sending limits while using Google Apps That is all for now . Once everything is in place WordPress will start sending using the Gmail credentials supplied over here.