ehlo method

Future<SmtpResponse> ehlo()

Issues the enhanced helo command to find out the service capabilities

EHLO or HELO always needs to be the first command that is sent to the SMTP server.

Implementation

Future<SmtpResponse> ehlo() async {
  final result = await sendCommand(SmtpEhloCommand(_clientDomain));
  // A fresh EHLO replaces everything announced before, in particular the
  // capabilities received in clear text before STARTTLS (RFC 3207 4.2).
  serverInfo
    ..capabilities = <String>[]
    ..authMechanisms = <AuthMechanism>[]
    ..maxMessageSize = null;
  for (final line in result.responseLines) {
    if (line.code == 250) {
      serverInfo.capabilities.add(line.message);
      if (line.message.startsWith('AUTH ')) {
        if (line.message.contains('PLAIN')) {
          serverInfo.authMechanisms.add(AuthMechanism.plain);
        }
        if (line.message.contains('LOGIN')) {
          serverInfo.authMechanisms.add(AuthMechanism.login);
        }
        if (line.message.contains('CRAM-MD5')) {
          serverInfo.authMechanisms.add(AuthMechanism.cramMd5);
        }
        if (line.message.contains('XOAUTH2')) {
          serverInfo.authMechanisms.add(AuthMechanism.xoauth2);
        }
      } else if (line.message.startsWith('SIZE ')) {
        final maxSizeText = line.message.substring('SIZE '.length);
        serverInfo.maxMessageSize = int.tryParse(maxSizeText);
      }
    }
  }

  return result;
}