Salesforce - Marketo records mismatch

Hi Team,
Quick question - 

There is a scenario where we faced in one of the campaigns. There were totally 16K records in a SFDC campaign and while flowing into the Marketo campaign around 180 records didn't flow through from Salesforce to Marketo Campaign. But these 180 records are present in Marketo database.

In these 180 records, there are -
1) Invalid email address
2) Inactive contacts
3) Duplicates.

But we tried to compare that with the records which flow through SF -> Marketo campaign which has all these.

Please anyone could let me know the reason for this? 

Thanks in Advance.