I am using DNN v7.3.3 and integrating with SendGrid SMTP over port 465 for SSL connections. I had the following settings in DNN:
SMTP Server: smtp.sendgrid.net:465
Connection Limit: 1
Max Idle Time: 0
Enable SSL: Yes
SMTP Authentication: Basic
SMTP Authentication Username / Password: (provided)
Running a test email did not go through and DNN had the following exception:
System.Net.Mail.SmtpException: The operation has timed out.
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at DotNetNuke.Services.Mail.Mail.SendMailInternal(MailMessage mailMessage, String subject, String body, MailPriority priority, MailFormat bodyFormat, Encoding bodyEncoding, IEnumerable`1 attachments, String smtpServer, String smtpAuthentication, String smtpUsername, String smtpPassword, Boolean smtpEnableSSL)
Is DNN using .Net library System.Net.Mail to send email. Reading from MSDN the library only supports "Explicit SSL" not "Implicit SSL".
Is it possible to use "Implicit SSL" in DNN?