Custom Field for Newsletter Permission & Manually Adding Email Addresseses to MailChimp

Hi, I just wanted to ask if something was possible. A little background info first.

I have three email lists for our community, one for our RocketChat implementation, one for our forum and another for the MailChimp signup form on our main website. Currently I am forced to send out 3 separate emails from each platform if I need to make an announcement. The problem with doing this is that many members are signed up to all three platforms, so they end up receiving duplicate emails.

What I would like to do to resolve this is to merge the email lists from our chat and forum into the MailChimp list so that I only need to send out one email to everyone. I already figured out how to do this for our forum, but I'm unsure about RocketChat.

The problem I'm having is that I need to have some kind of custom field during registration where new users give their permission to receive the newsletter, such as a checkbox. The reason for this is because I'm not allowed to send people emails on MailChimp unless they give their permission first.

In addition to this, I need to be able to see a list of the newest members and if they gave permission or not. If they did not give permission, I skip them. If they did give permission however, I would manually add their email address to the MailChimp list. I would check this list from day to day in order to keep the MailChimp list updated. Does anyone know if any of this is possible with RocketChat?

If not, it seems the only thing I can do then is to send emails both through RocketChat and MailChimp, which will cause duplicates. I'd like to avoid that if possible. I'd appreciate any help, thanks.

No files, tests, or implementation entry points are named. Start by examining Rocket.Chat's registration flow and member-list or administration entry points to determine whether consent can be collected and viewed. Done would require a defined way to record newsletter permission and identify consenting members for manual MailChimp updates.