Embedding more text into the mail body in SMTP Gmail sender

I am using Gmail sender function defined here to send a mail to the predefined mail id. But my problem is that i want to embed more text into the body of my mail... The Gmail sender is only accepting one sting to be embedded into the body of the mail. Can anyone tell me how to embed more strings into the body of the mail... If Gmail sender is not efficient method to send a mail then please suggest me an alternative with an example....开发者_StackOverflow中文版

Probably try something like "this" + "\n" + "that"