First, get an app that integrates Mailchimp with Shopify. Mailchimp has a list of 3rd party apps here: https://mailchimp.com/help/shopify-workarounds/
That will ensure that you are getting all your emails to the right place.
Secondly, if someone is receiving 4 emails when she places an order, then odds are you have order confirmations running from more than one place. Check to see if Shopify and Mailchimp are both sending out email order confirmations.
Also, it sounds like you need to de-dupe your list. Import anything from Shopify into Mailchimp so that all the email addresses are in the same place, then follow the tutorial here: https://mailchimp.com/help/remove-duplicates-and-bounces-with-excel/
This tutorial also shows you how to de-dupe in case you have duplicate customers in Shopify: https://www.youtube.com/watch?v=rU7vM_4MyE8
If you remove all the duplicate email addresses and review your workflows to make sure that only one service is sending out emails, then you should be able to reign in all the extra contacts and emails that are going on.
Hey @harleysbakery !
At first I'd download all my emails from all platforms that I may have used to collect them.
Then once you merge the files and create a new one with all your emails, choose a platform like Klaviyo or whatever an upload these emails.
Now, on your live website pick an application that helps you create popups and signup forms, I'd suggest Privy.
Then, integrate this app and have all the signups directly sent to your Klaviyo or any other email provider you've chosen to work with.
You can also integrate it with Flashchat the facebook messenger marketing app and grow simultaneously your Facebook messenger list.
Now, with regard your segmentation I'd initially suggest have an automated flow for abandoned carts and welcoming new subscribers. Last, you need a different segment for existing customers to market them any new offers for activating them again.
Hope this helps.