Im using an .NET application which reads emails from a specific mail box (using WebDAV) and downloads the attachments found in the customer email and copies it to the destination share folder. It also sends an acknowledgement back to the customer. Im facing an issue where in the customer emails with attachments are getting rejected. This happened after we upgraded out mail server to exchange server 2007. It was working fine prior to that. Issue in Detail: The following piece of code [written in VB.NET] fails and generates the below error exception. '-- Download the Attachment and save as local copy webc = New System.Net.WebClient webc.Credentials = MyCredentialCache data = webc.DownloadData( strAttachURI ) <------ Fails Here stringdata = System.Text.Encoding.ASCII.GetString(data) FileOpen(hfile, strLocalFile, OpenMode.Binary, OpenAccess.Write) FilePut(hfile, data) FileClose(hfile) Error code returned: err.description - The remote server returned an error: (400) Bad Request. err.HelpContext - 0 err.Number - 5 err.Source - System Value of strAttachURI string looks as follows: http://myexchgServerID.domain.com/exchange/testUsr/MSEA/200612040458562006120404533320061204043834[Test%20Mail]%20SRQ061120602152%20bySudha.EML/My%20Txt%20File.txt?attach=1 This String value points to the URI email attachment path found in the Mailbox that needs to be downloaded. I suspect if some configuration settings or an alternative approach that could fix this issue. Please advice. Thank you in advance.