How does Marketo define an invalid email address?

[Anonymous]

We are setting up our lead lifecycle to have invalid emails go to 'trash', and were wondering how Marketo defines what an "invalid email" is?

Thanks!

[Anonymous]

Anything not deliverable due to something that is not a temporary technical difficulty.  Malformed, no such domain, no such user, etc.  May not want to just trash them, a lot of times it's just a typo you can easily spot (con for com, things like that).

[Josh_Hill13]

I summarized Marketo's details in this document.
http://www.slideshare.net/jdavidhill/marketo-email-reputation-management