How do you send an email to a list of people who did not open a specific set of emails?

[Anonymous]

I am trying to send an email to people who did not open email A or email B. I see how to send to a list of people who *DID* open these emails, but not how to send to people who did not. If I put "opened email" as a filter and the names of the emails - my only options are "IS" that email (for they did open it) or "IS NOT" the email - as in they've opened emails that are not the these two emails, I think. How do I tell Marketo to send to a list of people who HAVEN'T opened these two emails? Thank  you.

[Dory_Viscoglio]

Hi Adena, there are inactivity filters that you can use for this: Not Opened Email, or Not Was Sent Email. These should be all the way at the bottom of the list of filters. You can also find them easily by just typing "Not" into the search box. 

[Josh_Hill13]

if you want to send to the people that you sent the email to, but did not open, you must be careful:

Was Sent Email IS X
AND
NOT Opened Email IS X

will return the correct people

if you just did Not Opened Email IS X, it will return EVERYONE who never tried to open that, including people who never got the email in the first place, which will be 98% of your database.