How do I email family heads concerning their juniors?

Juniors are typically not listed in Mailchimp because they may not have an email. In fact any family member need not have an email (the family head always does).

So if you wanted to contact all parents of Juniors who are members, say, how could I do it? The answer is that MMM records the membership category of family members (who lack an email) against the family head. So you could select a segment where "Products & subscriptions" contained junior memberships and you would capture the family heads as required.

Similarly, a family head is deemed a member on Mailchimp if any one of their family members is a member. This ensures that mail outs filtered by "current member" will reach parents of juniors (who are members) even if the parent is not a member.

The same goes for event participation - any event an email-less family member is taking part in is recorded against the family head.

But there may be other situations where you wanted to email the family heads of a set of juniors. For example, juniors who have recently left the club. You can use tags to achieve this: Everyone linked to the club is listed in the MMM Members listings. There you can filter and tag for the set of family members you wish to email. When MMM synchronises with Mailchimp, these tags are transferred to the family head (assuming the family member does not have an email). In Mailchimp you will see the family heads tagged appropriately and you can choose your campaign mail-out to send to contacts with that specific tag.