/// <summary>
/// Attempt to connect to the specified MX server.
/// </summary>
/// <param name="mx">MX Record of the server to connect to.</param>
public async Task <bool> ConnectAsync(MXRecord mx)
{
_LastActive = DateTime.UtcNow;
IsActive = true;
await base.ConnectAsync(mx.Host, MtaParameters.Client.SMTP_PORT);
_LastActive = DateTime.UtcNow;
SmtpStream = new SmtpStreamHandler(this as TcpClient);
_MXRecord = mx;
// Read the Server greeting.
string response = SmtpStream.ReadAllLines();
_LastActive = DateTime.UtcNow;
if (!response.StartsWith("2"))
{
// If the MX is actively denying use service access, SMTP code 421 then we should inform
// the ServiceNotAvailableManager manager so it limits our attepts to this MX to 1/minute.
if (response.StartsWith("421"))
{
ServiceNotAvailableManager.Add(SmtpStream.LocalAddress.ToString(), MXRecord.Host, DateTime.UtcNow);
}
base.Close();
return(false);
}
IsActive = false;
_LastActive = DateTime.UtcNow;
return(true);
}
/// <summary>
/// Attempt to connect to the specified MX server.
/// </summary>
/// <param name="mx">MX Record of the server to connect to.</param>
private async Task <MantaOutboundClientSendResult> ConnectAsync()
{
TcpClient = CreateTcpClient();
try
{
await TcpClient.ConnectAsync(_MXRecord.Host, MtaParameters.Client.SMTP_PORT);
}
catch (Exception)
{
return(new MantaOutboundClientSendResult(MantaOutboundClientResult.FailedToConnect, "421 Failed to connect", _VirtualMta, _MXRecord));
}
SmtpStream = new SmtpStreamHandler(TcpClient);
// Read the Server greeting.
string response = SmtpStream.ReadAllLines();
// Check we get a valid banner.
if (!response.StartsWith("2"))
{
TcpClient.Close();
// If the MX is actively denying use service access, SMTP code 421 then we should inform
// the ServiceNotAvailableManager manager so it limits our attepts to this MX to 1/minute.
if (response.StartsWith("421"))
{
return(new MantaOutboundClientSendResult(MantaOutboundClientResult.ServiceNotAvalible, response, _VirtualMta, _MXRecord));
}
return(new MantaOutboundClientSendResult(MantaOutboundClientResult.FailedToConnect, response, _VirtualMta, _MXRecord));
}
// We have connected, so say helli
return(await ExecHeloAsync());
}
