public EnvelopeCollection DownloadEnvelopes(
	string messageIndexSet,
	bool indexIsUid,
	EnvelopeParts parts,
	int bodyPreviewSize
)

Public Function DownloadEnvelopes ( 
	messageIndexSet As String,
	indexIsUid As Boolean,
	parts As EnvelopeParts,
	bodyPreviewSize As Integer
) As EnvelopeCollection

using System;
using MailBee;
using MailBee.ImapMail;
using MailBee.Mime;

class Sample
{
    static void Main(string[] args)
    {
        Imap imp = new Imap();

        imp.Connect("mail.company.com");

        imp.Login("jdoe", "secret");

        // Select Inbox folder.
        imp.SelectFolder("Inbox");

        // Download body structure (header + 1000 bytes of the body), message preview,
        // and the date assigned to the message by the server (usually, it's the date
        // when the message was received by the server).
        EnvelopeCollection envs = imp.DownloadEnvelopes(Imap.AllMessages, false,
            EnvelopeParts.BodyStructure | EnvelopeParts.MessagePreview | EnvelopeParts.InternalDate,
            1000);

        foreach (Envelope env in envs)
        {
            Console.WriteLine("Message #" + env.MessageNumber + " info:");
            if (env.IsValid)
            {
                // Tell MailBee to create plain-text version of HTML message
                // if plain-text version is not available in the message.
                // It's important to set this before the message gets parsed
                // (which occurs automatically when any element of the message
                // is accessed though MailMessage object properties or methods).
                // If you change HtmlToPlainMode after the message has already been parsed,
                // call MailMessage.Parser.Apply to reparse the message with new settings.
                env.MessagePreview.Parser.HtmlToPlainMode = HtmlToPlainAutoConvert.IfNoPlain;

                Console.WriteLine("From: " + env.MessagePreview.From.ToString());
                Console.WriteLine("To: " + env.MessagePreview.To.ToString());
                Console.WriteLine("Subject: " + env.MessagePreview.Subject);
                Console.WriteLine("Composed at: " + env.MessagePreview.Date);

                // We use DateReceived from INTERNALDATE item of FETCH response.
                // We could have also used env.MessagePreview.DateReceived instead
                // (it's obtained from "Received:" headers of the message).
                // However, env.MessagePreview.DateReceived is DateTime.MinValue
                // when the message does not contain "Received:" headers.
                // INTERNALDATE, on other hand, is always available in IMAP4.
                // MailMessage.DateReceived still makes sense because INTERNALDATE
                // is not available in POP3, and examining "Received:" headers is
                // the only way of getting this info when using POP3 protocol.
                Console.WriteLine("Received at: " + env.DateReceived);

                if (env.MessagePreview.Priority >= MailPriority.High)
                {
                    Console.WriteLine("The message is high priority");
                }

                // Determine if the message has attachments.
                bool hasAttachments = false;
                ImapBodyStructureCollection parts = env.BodyStructure.GetAllParts();
                foreach (ImapBodyStructure part in parts)
                {
                    // Detect if this part is attachment.
                    if ((part.Disposition != null && part.Disposition.ToLower() == "attachment") ||
                        (part.Filename != null && part.Filename != string.Empty) ||
                        (part.ContentType != null && part.ContentType.ToLower() == "message/rfc822"))
                    {
                        hasAttachments = true;
                        break;
                    }
                }
                if (hasAttachments)
                {
                    Console.WriteLine("The message has attachments.");
                }

                // Display first 250 characters of the text body. Note that we requested
                // 1000 bytes but now display only 250 characters. We request more than
                // we display because of:
                // - body section of MIME message may start with a block of additional
                // information which is not a part of text body. Usually, the length
                // of this block is 100-300 bytes.
                // - non-ASCII characters may occupy more than one byte.
                // In some cases, reading 1000 bytes may still be not enough to reach the
                // text body (for instance, if the message contains attachment which preceeds
                // the text body in the message source). In such rare cases, the body preview
                // will not be available (or, the developer may request more than 1000 bytes
                // of the body and thus increase network traffic). 
                string bodyPreview = env.MessagePreview.BodyPlainText;
                if (bodyPreview.Length > 250)
                {
                    bodyPreview = bodyPreview.Substring(0, 250);
                }
                Console.WriteLine();
                Console.WriteLine(bodyPreview);
            }
            else
            {
                Console.WriteLine("FETCH response contains some invalid data.");
            }
            Console.WriteLine("============================================================");
        }

        // Disconnect from the server.
        imp.Disconnect();
    }
}

Imports System
Imports MailBee
Imports MailBee.ImapMail
Imports MailBee.Mime

Module Sample
    Sub Main(ByVal args As String())
        Dim imp As New Imap

        imp.Connect("mail.company.com")

        imp.Login("jdoe", "secret")

        ' Select Inbox folder.
        imp.SelectFolder("Inbox")

        ' Download body structure (header + 1000 bytes of the body), message preview,
        ' and the date assigned to the message by the server (usually, it's the date
        ' when the message was received by the server).
        Dim envs As EnvelopeCollection = imp.DownloadEnvelopes(Imap.AllMessages, False, _
            EnvelopeParts.BodyStructure Or EnvelopeParts.MessagePreview Or EnvelopeParts.InternalDate, 1000)

        For Each env As Envelope In envs
            Console.WriteLine("Message #" & env.MessageNumber & " info:")
            If env.IsValid Then
                ' Tell MailBee to create plain-text version of HTML message
                ' if plain-text version is not available in the message.
                ' It's important to set this before the message gets parsed
                ' (which occurs automatically when any element of the message
                ' is accessed though MailMessage object properties or methods).
                ' If you change HtmlToPlainMode after the message has already been parsed,
                ' call MailMessage.Parser.Apply to re-parse the message with new settings.
                env.MessagePreview.Parser.HtmlToPlainMode = HtmlToPlainAutoConvert.IfNoPlain

                Console.WriteLine("From: " & env.MessagePreview.From.ToString())
                Console.WriteLine("To: " & env.MessagePreview.To.ToString())
                Console.WriteLine("Subject: " & env.MessagePreview.Subject)
                Console.WriteLine("Composed at: " & env.MessagePreview.Date)

                ' We use DateReceived from INTERNALDATE item of FETCH response.
                ' We could have also used env.MessagePreview.DateReceived instead
                ' (it's obtained from "Received:" headers of the message).
                ' However, env.MessagePreview.DateReceived is DateTime.MinValue
                ' when the message does not contain "Received:" headers.
                ' INTERNALDATE, on other hand, is always available in IMAP4.
                ' MailMessage.DateReceived still makes sense because INTERNALDATE
                ' is not available in POP3, and examining "Received:" headers is
                ' the only way of getting this info when using POP3 protocol.
                Console.WriteLine("Received at: " & env.DateReceived)

                If env.MessagePreview.Priority >= MailPriority.High Then
                    Console.WriteLine("The message is high priority")
                End If

                ' Determine if the message has attachments.
                Dim hasAttachments As Boolean = False
                Dim parts As ImapBodyStructureCollection = env.BodyStructure.GetAllParts()
                For Each part As ImapBodyStructure In parts
                    ' Detect if this part is attachment.
                    If (Not part.Disposition Is Nothing AndAlso part.Disposition.ToLower() = "attachment") OrElse _
                        (Not part.Filename Is Nothing AndAlso part.Filename <> String.Empty) OrElse _
                        (Not part.ContentType Is Nothing AndAlso part.ContentType.ToLower() = "message/rfc822") Then

                        hasAttachments = True
                        Exit For
                    End If
                Next
                If hasAttachments Then
                    Console.WriteLine("The message has attachments.")
                End If

                ' Display first 250 characters of the text body. Note that we requested
                ' 1000 bytes but now display only 250 characters. We request more than
                ' we display because of:
                ' - body section of MIME message may start with a block of additional
                ' information which is not a part of text body. Usually, the length
                ' of this block is 100-300 bytes.
                ' - non-ASCII characters may occupy more than one byte.
                ' In some cases, reading 1000 bytes may still be not enough to reach the
                ' text body (for instance, if the message contains attachment which preceeds
                ' the text body in the message source). In such rare cases, the body preview
                ' will not be available (or, the developer may request more than 1000 bytes
                ' of the body and thus increase network traffic). 
                Dim bodyPreview As String = env.MessagePreview.BodyPlainText
                If bodyPreview.Length > 250 Then
                    bodyPreview = bodyPreview.Substring(0, 250)
                End If
                Console.WriteLine()
                Console.WriteLine(bodyPreview)
            Else
                Console.WriteLine("FETCH response contains some invalid data.")
            End If

            Console.WriteLine("============================================================")
        Next

        ' Disconnect from the server.
        imp.Disconnect()
    End Sub
End Module