Exemplos por driver:
smtp: { "host":"smtp.example.com", "port":587, "user":"...", "pass":"..." }
brevo: { "apiKey":"xkeysib-..." }
resend: { "apiKey":"re_..." }
ses: { "region":"us-east-1", "accessKeyId":"...", "secretAccessKey":"..." }
sender: { "host":"smtp.sender.net", "port":587, "user":"...", "pass":"..." }
sendpulse: { "host":"smtp-pulse.com", "port":465, "secure":true, "user":"...", "pass":"..." }
mailjet: { "host":"in-v3.mailjet.com", "port":587, "user":"<api-key>", "pass":"<secret>" }
mailtrap: { "host":"live.smtp.mailtrap.io", "port":587, "user":"api", "pass":"..." }
smtp2go: { "host":"mail.smtp2go.com", "port":2525, "user":"...", "pass":"..." }
postmark: { "host":"smtp.postmarkapp.com", "port":587, "user":"<token>", "pass":"<token>" }
mailersend: { "host":"smtp.mailersend.net", "port":587, "user":"...", "pass":"..." }