Email subscription problem

Can anyone help with this – we’d be really grateful.

Since moving over to a self hosted wordpress site our email subscribers that we moved over with no longer receive blog post emails. New subscribers who have signed up since we made the change do. We can see the subscribers but we have no idea why they are not getting the mail.

When we have tried entering our email address to sign up for post alerts we receive the message saying we have opted out of receiving them which we have not.

My site is https://www.littlebuttondiaries.com

Thank you!!!