Here are ultimtae list of smtps
https://www.smtp.com/pricing/ the best!
https://smtpserver.com/
https://sendunlimitedemail.com/
https://serversmtp.com/
https://www.mailgun.com/pricing/
https://www.smtp2go.com/benefit/smtp-server/
https://messagebird.com/ Messagebird Sparkspot free $20 50k/m ∞ subs
https://www.mailersend.com/pricing
https://www.mailjet.com/
https://postmarkapp.com/
https://elasticemail.com/
https://www.mailercloud.com/pricing
https://www.newsmanapp.com/pricing
https://sendgrid.com/
https://emailoctopus.com/
https://sendy.co/
https://sendmails.io/
https://mailbluster.com/
https://mailtrap.io/pricing
https://myinboxpro.com/price-plan