I've selected what I'm sure are all the right fields, and issued the sync multiple times now, however nothing is pushing through to Mailchimp.

I also require Mailchimp lists to sync through to CRM, but I'm sure the sync will not work on this also.

Another question I have in addition to this,

If I send an email to a customer from mailchimp who is also on the CRM - will there be a way of knowing if that customer has been sent an email which automatically syncs through?