I see that sendgrid free plan is going to be decomissioned.
I use to send about 1-5 emails per month and their costs will be super high for me.

1) Can emailit be an alternative?

I am using Sendgrid now in my shop (very few sales, but still). When a person buys something an email is sent to me and them via sendgrid API.

2) Can emailit be an alternative, or emailit is more like Mailerlite to manage newsletter campaigns? Or both?

3) Sendgris also has marketing emails. For example people that buy product X are receiving 10 emails, one per week. Then stop. Can emailit do the same?