• 4 Troubleshooting System.Web.Mail
• 4.1 A Word About Exceptions (READ THIS FIRST)
• 4.2 Namespace/COM/DLL Related Exceptions
• 4.2.1 Error loading type library/DLL.
• 4.2.10 "Could not access 'CDO.Message' Object - Part 8
• 4.2.11 "Could not access 'CDO.Message' Object - Part 9
• 4.2.12 "Could not access 'CDO.Message' Object - Part 10
• 4.2.13 "Could not access 'CDO.Message' Object - Part 11
• 4.2.2 The "SendUsing" configuration value is invalid.
• 4.2.3 The scary "Could not access 'CDO.Message' object"
• 4.2.4 "Could not access 'CDO.Message' Object - Part 2
• 4.2.5 "Could not access 'CDO.Message' Object - Part 3
• 4.2.6 "Could not access 'CDO.Message' Object - Part 4
• 4.2.7 "Could not access 'CDO.Message' Object - Part 5
• 4.2.8 "Could not access 'CDO.Message' Object - Part 6
• 4.2.9 "Could not access 'CDO.Message' Object - Part 7
• 4.3 SMTP Protocol/Network Related Exceptions
* You Are Here *   [ Scroll To Answer ]   [  Discuss  ]  
• 4.3.1 The server specified in the SmtpServer property is not valid or not available
• 4.3.10 Can send locally but not externally.
• 4.3.11 550 x.x.x Unable to relay for xxxxx.
• 4.3.2 [COMException (0x8004020f): The server rejected one or more recipient addresses."]
• 4.3.3 Some of emails are rejected by some clients, but not all.
• 4.3.4 My mail server requires authentication. (503 This mail server requires authentication)
• 4.3.5 Not a gateway or local host.
• 4.3.6 The specified protocol is unknown.
• 4.3.7 The specified protocol is unknown. Part 2
• 4.3.8 The server response was 452 Filesystem error - message not accepted.
• 4.3.9 The transport failed to connect to the server.
• 4.4 Other Problems/Exceptions
• 4.4.1 How can I stream attachments into the MailMessage?
• 4.4.2 How can I create an attachment from a string?
• 4.4.3 Why does System.Web.Mail work in development and not in production?
• 4.4.4 I keep getting question marks (?'s) in my email, where characters should be.
• 4.4.5 System.Web.Mail is truncating the message body.
• 4.4.6 Attachments added to the MailMessge are corrupt.
• 4.4.7 All of my emails are ending up in the /badmail directory.
• 4.4.8 System.Web.Mail is corrupting my PDF attachments, what gives?

4.3 SMTP Protocol/Network Related Exceptions Printer Friendly   Email This FAQ   Discuss

The formatted version of this faq can be found at http://www.SystemWebMail.com/faq/4.3.aspx