Can you give us some more information?
This is not very clear.
for example an email that is firstname.lastname@example.org or an email that is jhon@hotmail, are they blocked from Marketo?
In addition if we have on the same program 2 leads with the same email during the emali blast what will happen?
We have programs with leads with the same email because leads are imported automatically from salesforce.
Thank you for your feedback
Blocked leads are people in the Marketo database that are marked blacklisted, unsubscribed, marketing suspended, and that have invalid/empty email.
test.com is not an invalid domain in any way, and there's no reason to expect that mail won't be sent to it!
The only expressly invalid TLD is .invalid. Read more here: http://blog.teknkl.com/be-smart-about-dummy-emails/