amazon function
Send through Amazon Simple Email Service (Amazon SES).
Region is the AWS region, e.g. 'us-east-1', or 'eu-west-1'.
Implementation
SmtpServer amazon(String accessKeyId, String secretKey, String region) =>
SmtpServer(
'email-smtp.$region.amazonaws.com',
username: accessKeyId,
password: _smtpPassword(secretKey, region),
);