Hi @TerryT,
There’s no way to generally filter for contacts that should’ve received an email but haven’t. For that, you would have to open individual marketing email sends, click into the Recipients tab, then into the Not sent section, and (for each send) create a static list of contacts who were not sent that email because of missing marketing contact status.
If you generally assume that these contacts should’ve been on any recipient list in a given time frame, you could simply filter for contacts where the following is the case:
- Last marketing email send date is unknown OR Last marketing email send date is more than (for example) 365 days ago
AND - Unsubscribed from all email is not equal to True
AND - Invalid email is not equal to True
AND - Email is known
AND - Email hard bounce reason is unknown
AND - Marketing contact status is Non-marketing contact
AND - Opted out of email: Marketing information is not equal to True
Keep in mind that none of the criteria above are checking for an actual legal basis to send emails to these contacts - which is required most countries of the world as far as I know. The absence of negative criteria does not mean there is a legal basis, just that these are technically eligible to receive emails. (My reply does not constitute legal advice.)
Best regards