I have been several times to sync CRM contacts into Campaigns and make segmentation. 

When I Sync the contacts, there are always 'Invalid Contacts' that do not get fetched into campaigns moddule. Why is this happening? and How do I know which contacts are invalid?

Another question. I am unable to Sync the leads from CRM into Campaigns. I map the fields properly (Lead Status to Lead Status) but they do not hetch properly. Why might be this happening and How can I solve it?

Thanks

Peter