/// <summary>
/// Parses the MessageBody as a Multipart message.
/// This method will add these parts as Attachments
/// </summary>
private void ParseMultipartMessageBody()
{
string multipartBoundary = Headers.ContentType.Boundary;
if (string.IsNullOrEmpty(multipartBoundary))
throw new ArgumentException("The body is a multipart message, but there is no multipart boundary");
int indexOfAttachmentStart = 0;
bool moreParts = true;
// Keep working until we have parsed every message part in this message
while(moreParts)
{
// Find the start of the message parts multipartBoundary
indexOfAttachmentStart = RawMessageBody.IndexOf(multipartBoundary, indexOfAttachmentStart);
if(indexOfAttachmentStart == -1)
throw new ArgumentException("The start of the attachment could not be found");
// Find the start of this message part - which does not include the multipartBoundary or the trailing CRLF
indexOfAttachmentStart = indexOfAttachmentStart + multipartBoundary.Length + "\r\n".Length;
// Find the end of the attachment, were we do not want the last line
int indexOfAttachmentEnd = RawMessageBody.IndexOf(multipartBoundary, indexOfAttachmentStart);
if(indexOfAttachmentEnd == -1)
throw new ArgumentException("The end of the attachment could not be found");
// Check if this is the last part, which ends with the multipartBoundary followed by "--"
if(RawMessageBody.Substring(indexOfAttachmentEnd).StartsWith(multipartBoundary + "--"))
moreParts = false;
// Calculate the length. We do not want to include the last "\r\n" in the attachment
int attachmentLength = indexOfAttachmentEnd - indexOfAttachmentStart - "\r\n".Length;
string messagePart = RawMessageBody.Substring(indexOfAttachmentStart, attachmentLength);
Attachment att = new Attachment(messagePart, Headers);
// Check if this is the MS-TNEF attachment type
// which has ContentType application/ms-tnef
// and also if we should decode it
if(MIMETypes.IsMSTNEF(att.Headers.ContentType.MediaType) && AutoDecodeMSTNEF)
{
// It was a MS-TNEF attachment. Now we should parse it.
TNEFParser tnef = new TNEFParser(att.DecodedAsBytes());
if (tnef.Parse())
{
// ms-tnef attachment might contain multiple attachments inside it
foreach (TNEFAttachment tatt in tnef.Attachments())
{
Attachment attNew = new Attachment(tatt.FileContent, tatt.FileName, MIMETypes.GetMimeType(tatt.FileName));
Attachments.Add(attNew);
}
}
else
throw new ArgumentException("Could not parse TNEF attachment");
}
else if(IsMIMEMailFile2(att))
{
// The attachment itself is a multipart message
// Parse it as such, and take the attachments from it
// and add it to our message
// This will in reality flatten the structure
Message m = att.DecodeAsMessage(true,true);
foreach (Attachment attachment in m.Attachments)
Attachments.Add(attachment);
}
else
{
// This must be an attachment
Attachments.Add(att);
}
}
}
