/// <summary>
/// Construct secified mime entity ENVELOPE string.
/// </summary>
/// <param name="entity">Mime entity.</param>
/// <returns></returns>
public static string ConstructEnvelope(MimeEntity entity)
{
/* RFC 3501 7.4.2
* ENVELOPE
* A parenthesized list that describes the envelope structure of a
* message. This is computed by the server by parsing the
* [RFC-2822] header into the component parts, defaulting various
* fields as necessary.
*
* The fields of the envelope structure are in the following
* order: date, subject, from, sender, reply-to, to, cc, bcc,
* in-reply-to, and message-id. The date, subject, in-reply-to,
* and message-id fields are strings. The from, sender, reply-to,
* to, cc, and bcc fields are parenthesized lists of address
* structures.
*
* An address structure is a parenthesized list that describes an
* electronic mail address. The fields of an address structure
* are in the following order: personal name, [SMTP]
* at-domain-list (source route), mailbox name, and host name.
*
* [RFC-2822] group syntax is indicated by a special form of
* address structure in which the host name field is NIL. If the
* mailbox name field is also NIL, this is an end of group marker
* (semi-colon in RFC 822 syntax). If the mailbox name field is
* non-NIL, this is a start of group marker, and the mailbox name
* field holds the group name phrase.
*
* If the Date, Subject, In-Reply-To, and Message-ID header lines
* are absent in the [RFC-2822] header, the corresponding member
* of the envelope is NIL; if these header lines are present but
* empty the corresponding member of the envelope is the empty
* string.
*
* Note: some servers may return a NIL envelope member in the
* "present but empty" case. Clients SHOULD treat NIL and
* empty string as identical.
*
* Note: [RFC-2822] requires that all messages have a valid
* Date header. Therefore, the date member in the envelope can
* not be NIL or the empty string.
*
* Note: [RFC-2822] requires that the In-Reply-To and
* Message-ID headers, if present, have non-empty content.
* Therefore, the in-reply-to and message-id members in the
* envelope can not be the empty string.
*
* If the From, To, cc, and bcc header lines are absent in the
* [RFC-2822] header, or are present but empty, the corresponding
* member of the envelope is NIL.
*
* If the Sender or Reply-To lines are absent in the [RFC-2822]
* header, or are present but empty, the server sets the
* corresponding member of the envelope to be the same value as
* the from member (the client is not expected to know to do
* this).
*
* Note: [RFC-2822] requires that all messages have a valid
* From header. Therefore, the from, sender, and reply-to
* members in the envelope can not be NIL.
*
* ENVELOPE ("date" "subject" from sender reply-to to cc bcc "in-reply-to" "messageID")
*/
// NOTE: all header fields and parameters must in ENCODED form !!!
StringBuilder retVal = new StringBuilder();
retVal.Append("(");
// date
if (entity.Header.Contains("Date:"))
{
retVal.Append(TextUtils.QuoteString(MimeUtils.DateTimeToRfc2822(entity.Date)));
}
else
{
retVal.Append("NIL");
}
// subject
if (entity.Subject != null)
{
retVal.Append(" " + TextUtils.QuoteString(MimeUtils.EncodeHeaderField(entity.Subject)));
}
else
{
retVal.Append(" NIL");
}
// from
if (entity.From != null && entity.From.Count > 0)
{
retVal.Append(" " + ConstructAddresses(entity.From));
}
else
{
retVal.Append(" NIL");
}
// sender
// NOTE: There is confusing part, according rfc 2822 Sender: is MailboxAddress and not AddressList.
if (entity.Sender != null)
{
retVal.Append(" (");
retVal.Append(ConstructAddress(entity.Sender));
retVal.Append(")");
}
else if (entity.From != null)
{
retVal.Append(" " + ConstructAddresses(entity.From));
}
else
{
retVal.Append(" NIL");
}
// reply-to
if (entity.ReplyTo != null)
{
retVal.Append(" " + ConstructAddresses(entity.ReplyTo));
}
else if (entity.From != null)
{
retVal.Append(" " + ConstructAddresses(entity.From));
}
else
{
retVal.Append(" NIL");
}
// to
if (entity.To != null && entity.To.Count > 0)
{
retVal.Append(" " + ConstructAddresses(entity.To));
}
else
{
retVal.Append(" NIL");
}
// cc
if (entity.Cc != null && entity.Cc.Count > 0)
{
retVal.Append(" " + ConstructAddresses(entity.Cc));
}
else
{
retVal.Append(" NIL");
}
// bcc
if (entity.Bcc != null && entity.Bcc.Count > 0)
{
retVal.Append(" " + ConstructAddresses(entity.Bcc));
}
else
{
retVal.Append(" NIL");
}
// in-reply-to
if (entity.InReplyTo != null)
{
retVal.Append(" " + TextUtils.QuoteString(MimeUtils.EncodeHeaderField(entity.InReplyTo)));
}
else
{
retVal.Append(" NIL");
}
// message-id
if (entity.MessageID != null)
{
retVal.Append(" " + TextUtils.QuoteString(MimeUtils.EncodeHeaderField(entity.MessageID)));
}
else
{
retVal.Append(" NIL");
}
retVal.Append(")");
return(retVal.ToString());
}