SMTP Problem since update v9

Hello everyone,

Since the v9 upgrade, I can no longer send mail. Mail reception is ok.
I tried on 2 different PCs, on my main pc, it doesn’t work but on other pc it works, so I don’t understand.

Here are the logs:

17:29:27.086|021|   SMTP S: 220 2.0.0 Ready to start TLS
17:29:27.124|021|   Exception: MailClient.Accounts.ConnectionException: La connexion a échoué pour la raison suivante:
17:29:27.124|021|     "Authentication failed, see inner exception."
17:29:27.124|021|    ---> System.Security.Authentication.AuthenticationException: Authentication failed, see inner exception.
17:29:27.124|021|    ---> System.ComponentModel.Win32Exception (0x80090302): La fonction demandée n’est pas prise en charge
17:29:27.124|021|      --- End of inner exception stack trace ---
17:29:27.124|021|      at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](TIOAdapter adapter, Boolean receiveFirst, Byte[] reAuthenticationData, Boolean isApm)
17:29:27.124|021|      at System.Net.Security.SslStream.AuthenticateAsClient(SslClientAuthenticationOptions sslClientAuthenticationOptions)
17:29:27.124|021|      at System.Net.Security.SslStream.AuthenticateAsClient(String targetHost, X509CertificateCollection clientCertificates, SslProtocols enabledSslProtocols, Boolean checkCertificateRevocation)
17:29:27.124|021|      at System.Net.Security.SslStream.AuthenticateAsClient(String targetHost)
17:29:27.124|021|      at MailClient.Protocols.Smtp.SmtpSendCommand.StartTls()
17:29:27.124|021|      at MailClient.Protocols.Smtp.SmtpSendCommand.Connect(WorkerStatus status)
17:29:27.124|021|      --- End of inner exception stack trace ---
17:29:27.124|021|      at MailClient.Protocols.Smtp.SmtpSendCommand.Connect(WorkerStatus status)
17:29:27.124|021|      at MailClient.Protocols.Smtp.SmtpSendCommand.Execute(WorkerStatus status)
17:29:27.125|021|      at MailClient.Commands.Command.Process(WorkerStatus status)
17:29:27.125|00B|   AccountBase.ChangeOnlineState : State changed to OFFLINE due BrokenConnection

Can you help me to fix this problem please ?
Thank you :slight_smile:

I have the same problem… Any soulution?
I see a Schannel fatal alert 70 at the same time as I tries to send mail.

As a test, can you completely disable any anti-virus, firewall, proxy or VPN, then try again.
Sometimes even restarting your router may resolve this.

Or, if you are using Windows 7, TLS 1.2 is disabled by default in your OS, and you will need to enable it. Instructions are here:

1 Like

I am using Windows 7 and enabling TLS 1.2 did the trick.