Oh man. Just from looking at the title, I had a feeling your might be in the adult space. The same happened to me. We were using Mailchimp to send technical newsletters to our registered developers.

I did try speaking with someone at Mailchimp to plead our case. Unfortunately it didn't work. You might have some luck though because you're more in the health & wellness area of the industry, whereas I own an adult app store, so I'm 100% in the "porn" side of it.

There are some adult friendly newsletter services out there, but they're usually very costly. I think I saw one a few years back that was $150 a month. We've been using Amazon SES to send verification emails for new registrations, so we opted for SES for our monthly dev newsletter, neither of which have any porn or adult content in them whatsoever.