We are also having this problem. Some employees receive it-some get it in the junk mail, and some don't get it at all.
I'm sorry to hear that some of your contacts are not receiving your emails. It sounds like it could be a Whitelisting issue. Here is an FAQ that will show you how to get Constant Contact Whitelisted for the recipient's domain's security protocol. We do recommend sending that FAQ to the recipient to have their IT professional Whitelist Constant Contact. If you have further questions about deliverability issues, we highly recommend calling our Deliverability experts, as they are best equipped to answer those queries.