newsletter plugin - smtp setting error

I am getting this error.

Note: for SMTP method - in "From email" you should use only emails which related with your SMTP server! Check it on "General Settings" and "Create\Edit newsletter"!

I am trying to use sendgrid. These are the settings.

host - smtp.sendgrid.net
user - lswishing
pass -

I don't have an email address @ sendgrid.net

What should I do?