The freelancer hired to set-up the initial flows was not careful enough. Too many mails were sent to the customers within a short timeframe, annoying the customer and putting the brand in danger for being flagged by google and Yahoo! as bulk sender. On top of that, the e-mails were designed in a way that makes it hard to change sections that are repeated in various e-mails (like dynamic product recommendations). For example, to change the CTA, we had to go through every single e-mail and change it manually, although this should be a global element that can be bulk changed across all flows.