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SMTP, IMAP, EWS, POP3, S/MIME .NET library

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IMAP - advanced features

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UIDPLUS extension 

Most modern IMAP servers implement the UIDPLUS extension This extension makes it possible to retrieve unique IDs of newly created messages when using CopyMessage, StoreMessage and StoreRawMessage methods. 

// create IMAP client instance, connect, log in
var imap = new Rebex.Net.Imap();
imap.Connect(hostname, SslMode.Implicit);
imap.Login(username, password);

// upload a message to "Inbox" folder
// Unique ID assigned to the message is returned by the method if supported by the server
string uniqueId = imap.StoreMessage("Inbox", mail);

// check whether UIDPLUS is supported and enabled
if ((imap.SupportedExtensions & imap.EnabledExtensions & ImapExtensions.UniqueIdPlus) ==
    ImapExtensions.UniqueIdPlus)
{
    Console.WriteLine("Message ID: {0}", uniqueId);
}

' create IMAP client instance, connect, log in
Dim imap As New Rebex.Net.Imap()
imap.Connect(hostname, SslMode.Implicit)
imap.Login(username, password)

' upload a message to "Inbox" folder
' Unique ID assigned to the message is returned by the method if supported by the server
Dim uniqueId As String = imap.StoreMessage("Inbox", mail)

' check whether UIDPLUS is supported and enabled
If (imap.SupportedExtensions And imap.EnabledExtensions And ImapExtensions.UniqueIdPlus) =
    ImapExtensions.UniqueIdPlus Then
    Console.WriteLine("Message ID: {0}", uniqueId)
End If

Custom commands 

The Imap object can execute custom commands, which makes it possible to utilize functionality not yet covered by Rebex API. To send a custom command use the Imap.SendCommand method. To read the response of this command use the Imap.ReadResponse method.

The following code uses SendCommand/ReadResonse methods to retrive Inbox quotas (if supported by the server): 

// create IMAP client instance, connect, log in
// ...

// determine Inbox quotas
imap.SendCommand("GETQUOTAROOT", "Inbox");
ImapResponse response = imap.ReadResponse();

// check the response code
if (response.Code != ImapResponseCode.Ok)
{
    Console.WriteLine("Command not understood.");
}
else
{
    // display Inbox quotas returned by the server
    foreach (ImapResponseLine line in response.GetLines())
    {
        if (line.Code == "QUOTA")
        {
            // Format: quote_root_name (resource_name current_usage limit)
            // Sample: "" (STORAGE 546615 7599416)
            Console.WriteLine(line.Parameters);
        }
    }
}

' create IMAP client instance, connect, log in
' ...

' determine Inbox quotas
imap.SendCommand("GETQUOTAROOT", "Inbox")
Dim response As ImapResponse = imap.ReadResponse()

' check the response code
If response.Code <> ImapResponseCode.Ok Then
    Console.WriteLine("Command not understood.")
Else
    ' display Inbox quotas returned by the server
    For Each line As ImapResponseLine In response.GetLines()
        If line.Code = "QUOTA" Then
            ' Format: quote_root_name (resource_name current_usage limit)
            ' Sample: "" (STORAGE 546615 7599416)
            Console.WriteLine(line.Parameters)
        End If
    Next
End If

Fine-tuning IMAP behavior 

Imap objects makes it possible to specify various low-level settings and workarounds.

Working with IMAP extensions 

IMAP protocol offers lots of extensions. To determine which extensions are supported by your IMAP server, use the Imap.SupportedExtensions property. By default, all supported extensions except Compression. To enable or disable some extensions, use the Imap.EnabledExtensions property. 

// create IMAP client instance and connect
// ...

// does the server support IDLE command?
bool idleSupported = (imap.SupportedExtensions & ImapExtensions.Idle) == ImapExtensions.Idle;

// disable UIDPLUS extension
imap.EnabledExtensions &= ~ImapExtensions.UniqueIdPlus;

' create IMAP client instance and connect
' ...

' does the server support IDLE command?
Dim idleSupported As Boolean = (imap.SupportedExtensions And ImapExtensions.Idle) = ImapExtensions.Idle

' disable UIDPLUS extension
imap.EnabledExtensions = imap.EnabledExtensions And Not ImapExtensions.UniqueIdPlus

Connecting to Exchange shared mailboxes 

To connect to a shared mailbox on Microsoft Exchange Server, use the following form of the Login method: 

// create IMAP client instance, connect
// ...

// authenticate to a shared mailbox
imap.Login("Domain/Username/AliasOfSharedMailbox", password);

// or use it like this (equivalent to above)
imap.Login("Username@Domain/AliasOfSharedMailbox", password);

' create IMAP client instance, connect
' ...

' authenticate to a shared mailbox
imap.Login("Domain/Username/AliasOfSharedMailbox", password)

' or use it like this (equivalent to above)
imap.Login("Username@Domain/AliasOfSharedMailbox", password)

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