Best smtp service to send contact form emails?

Hello,
I prefer not to send SMTP direct from my website server, and it is blocked by the hosting provider.
So can anyone recommend a smtp provider i can use with the kirby email contact form to send through? The contact form wont be used often, but i want to make sure it works every time it is used.
So if there is a provider with a free plan for low volume, that would be great. And one that i can configure with kirby emailer, so needs to accept standard smtp connections.

There’s a list of free providers here: 10 Best Free SMTP Servers for Transactional Emails in 2022

As far as I recall I tested Sendinblue and Mailgun in the past