Error-Message = "The SMTP server requires a secure connection

Question

Hi

I am getting below error - Message = "The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication Required. Learn more at"

Email.Body = BodyStr;

Email.BodyEncoding = Encoding.UTF8;
Email.IsBodyHtml = true;
Email.Priority = MailPriority.Normal;
SmtpClient sc = new SmtpClient(Result.SMTPHost, Convert.ToInt32(Result.SMTPPort));
sc.Credentials = new System.Net.NetworkCredential(Result.Email, "test");

sc.UseDefaultCredentials = false;
sc.EnableSsl = Convert.ToBoolean(Result.EnableSsl);

sc.Send(Email);

Thanks

Uttam Kumar · Answer

Google may block sign-in attempts from some apps or devices that do not use modern security standards. Since these apps and devices are easier to break into, blocking them helps keep your account safer. Therefore, you have to enable Less Secure Sign-In (or Less secure app access ) in your google account. After signing into your Google account, go to: https://www.google.com/settings/security/lesssecureapps or https://myaccount.google.com/lesssecureapps In C#, you can use the following code: using (MailMessage mail = new MailMessage()) { mail.From = new MailAddress("email@gmail.com"); mail.To.Add("somebody@domain.com"); mail.Subject = "Hello World"; mail.Body = " Hello "; mail.IsBodyHtml = true; mail.Attachments.Add(new Attachment("C:\file.zip")); using (SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587)) { smtp.Credentials = new NetworkCredential("email@gmail.com", "password"); smtp.EnableSsl = true; smtp.Send(mail); } }

Vishal Yelve · Answer

Hi Ramco, Please refer below link, hope this might help you. https://www.aspsnippets.com/Articles/Send-email-using-Gmail-SMTP-Mail-Server-in-ASPNet.aspx https://www.aspsnippets.com/Articles/GMAIL-Error-The-SMTP-server-requires-a-secure-connection-or-the-client-was-not-authenticated.aspx

Uday Dodiya · Answer

Sometimes google blocks the third party access, so you have to enable Less-Secure Sign In

Ramco Ramco · Answer

Hi Uttam I tried but still same problem, Below is my code Email.BodyEncoding = Encoding.UTF8; Email.IsBodyHtml = true; Email.Priority = MailPriority.Normal; SmtpClient sc = new SmtpClient("smtp.gmail.com", 587); sc.Credentials = new System.Net.NetworkCredential("test@gmail.com", "test123@"); sc.EnableSsl = true; sc.UseDefaultCredentials = false; sc.Send(Email); Thanks

Ramco Ramco · Answer

Hi Vishal Below is the code but still same problem , Even in Gmail i have set Less secure App Access = "On". Email.Body = BodyStr; Email.BodyEncoding = Encoding.UTF8; Email.IsBodyHtml = true; Email.Priority = MailPriority.Normal; SmtpClient sc = new SmtpClient("smtp.gmail.com", 587); sc.Credentials = new System.Net.NetworkCredential("test@gmail.com", "test123@"); sc.EnableSsl = true; sc.UseDefaultCredentials = false; sc.Send(Email); Thanks

Vishal Yelve · Answer

Try this, hope this will work sc.Credentials = new System.Net.NetworkCredential("your@gmail.com", "password"); sc.EnableSsl = true; sc.UseDefaultCredentials = false;

Ramco Ramco · Answer

Hi Even then same error Thanks

Vishal Yelve · Answer

Hi Ramco, try this by setting this ss.UseDefaultCredentials = true;