startTls method Null safety

Future<SmtpResponse> startTls()

Upgrades the current insure connection to SSL.

Opportunistic TLS (Transport Layer Security) refers to extensions in plain text communication protocols, which offer a way to upgrade a plain text connection to an encrypted (TLS or SSL) connection instead of using a separate port for encrypted communication.


Future<SmtpResponse> startTls() async {
  final response = await sendCommand(SmtpStartTlsCommand());
  if (response.isOkStatus) {
    log('STARTTL: upgrading socket to secure one...', initial: 'A');
    await upradeToSslSocket();
    await ehlo();
  return response;