I don't know why but last couple of days all your mails coming as SPAM mails. It may be happening with others too.
I checked with google.
There are two ways to avoid this:
1. go to your spam folder and click on the email from ""
On top of the mail, you will see the button 'NOT SPAM'
click on this.
2. Create a contact for firstname.lastname@example.org & email@example.com
These two (or any one of them) should do the trick