I can definitely understand how important it is for your contacts to receive your emails. I apologize contacts from this domain are bouncing. Have you tried whitelisting Constant Contact? Private domains like this tend to have stronger filter settings, so whitelisting is always a great step. We also have our Deliverability Specialists who can help look further into these contacts or any other contacts that may bounce in your account.
Frankie P. Community & Social Media Support
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