Best email marketing service for small businesses "i will not promote"

I'm currently on Mailchimp but I'm desperate to switch. I started on Mailchimp because it seemed easy to use, but I'm now realizing I need to pay extra if I want to do any actual email marketing. I'm looking for campaigns + transactional email, and my budget is fairly limited right now. I've looked into Sender and it seems like a good option, really generous free plan, but I'd like to get more insights from real users. I've also looked into Brevo, but I'm confused about automation limits. It says it's limit