Website for checking valid email addresses

[Cormac]

I remember using a website a year or so ago that could check the validity of an email address. If I remember correctly it had either a frog as its logo or a frog in the name of the app.

One of the things the site could do was to show how long ago the email address was created.

Any ideas about this website or a website that does something similar?

 

[Gavin]

Internet Frog can check to see if an email is valid although it doesn't give you the creation date.

 

[mneylon]

It gets confused by greylisting