smtpclient " failure sending mail"

Well, the "failure sending e-mail" should hopefully have a bit more detail. But there are a few things that could cause this.

  1. Restrictions on the "From" address. If you are using different from addresses, some could be blocked by your SMTP service from being able to send.
  2. Flood prevention on your SMTP service could be stopping the e-mails from going out.

Regardless if it is one of these or another error, you will want to look at the exception and inner exception to get a bit more detail.


apparently this problem got solved just by increasing queue size on my 3rd party smtp server. but the answer by Nip sounds like it is fairly usefull too