Brevo (formerly SendInBlue) seems to strike a good balance of features and price. I'm new at all this internet marketing malarky and trying to put the pieces together, but it seems like whilst ConvertKit is ubiquitous and well-regarded, Brevo might actually be more attractive for me. And, as there are some other tools I'd like to use that integrate with Brevo, I'd like to unify so that my E-Scribe white label app sign-ups are in Brevo too.