Some of our Europe-based customers are becoming uncomfortable with Mailchimp as it is hosted in the US. We hear a lot about Flexmail (https://flexmail.be/fr) which also offers basic marketing automation.
I reached out to them but they do not offer a pre-built connector. Instead, they recommend third-party integration services (Piesync etc) which are not hosted in the EU. Also, costs can be difficult to anticipate (often based on API calls).
Has any of you already developed a connector? Any experience on associated workload? Would you be willing to share the code (commercial conditions to be discussed of course)?
Mailjet and Sendinblue are also mentionned often... So the same question applies there.