My worpress.com followers don’t get my mails I have jetpack

I’ve a self hosted site and installed Mailpoet yesterday.
I disabled the “Subscriptions” and the “Comments” from Jetpack. I’ve built several templates of newsletter, created a list of subscribers but only used the people who were already following via mail. Once the new newsletter was launched, only my “mail” followers did get it. Not my WordPress.com followers. As I don’t have their mails and they did not ask explicitely to follow by mail I did not dare adding them to my “mail follower” list, even using a special plugin to collect their mails.

Today I tried something else and did not disable the “Subscription” option in Jetpack but only erased the “mail followers” on WordPress.com (not in my subscriber list in Mailpoet). Result: the wordpress followers did get my mails but with the Jetpack template, way less fun than my Mailpoet template.

How can I ensure that my “mail followers” and my “wordpress followers” get my Mailpoet newsletter? Do I have to as them explicitely if they’re OK with me using their mail??? Or can I presume as they’re following me that they did get all my mails before and install the plugin to gather their mails? Other?

Thanks for your reply.