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Question:

Email Blocked because Blacklisted?

May 13 '14 at 09:18

Good morning,

We are developing an independent platform for sending emails through our intranet system. So far, your product turns to be one of the best .NET components for our purposes.

I have a question for you:
Do you have a solution which provide us a feedback of sent emails through the component ?

Lets do an example:
An email being sent by using your component. That email has been received from the SMTP provider, but it turns to be blocked because it's blacklisted. Usually, by using a standard client email (Outlook, Thunderbird,.. ), an alert message back to the User which reads "your SMTP has been blacklisted... " or something like that. This is NOT a classical bounce message, which is being received in case of a wrong email address. We are not able to replicate this functionality by using your component. Seem that, once the email has been sent to the SMTP, we are no longer able to get the status of it. Beside,by reading your component' features ( from this page http://www.chilkatsoft.com/email-features.asp) we found these:

Are they used to monitor the status of an email? if yes, can you provide a sample about how to implement these features?


Answer

If the SMTP cilent-to-server exchange results in the SMTP server responding with an error status, then the call to SendEmail will return false/0, and the email is never sent. You can examine the mailman.LastErrorText for detailed information about what transpired. You can also examine the mailman.LastSmtpStatus integer property to get the SMTP status code.

If however, the SMTP client-to-server exchange proceeded without error -- meaning that the email was handed off to the SMTP server with recipients, etc. then from the client's perspective the email was "sent off". It is now in the SMTP server's hands to proceed with delivering the email. It may be that a mail server at the destination (or somewhere along the delivery route) rejects the email and sends a non-delivery receipt to the sender (which is the FROM address of the email, or the BounceAddress if the emailObject.BounceAddress property was set). It could also be that a mail server responds with a non-standard/ad-hoc auto-response to a rejected email. In all of these cases, the sender will receive some sort of response email indicating non-delivery. One possible way of handling these is to programmatically read the mailbox where these delivery notifications (bounces) arrive. Reading the mail can be achieved via Chilkat.MailMan (for POP3) or Chilkat.Imap (for IMAP), and then individual emails can be examined via Chilkat.Bounce to determine if it is an automated response, and if so, the general type.