Retrieve Email from IMAP4 server in C++/CLI/CLR

In previous section, I introduced retrieving email from POP3 server in C++/CLI/CLR. In this section, I will introduce the IMAP4 server.

Introduction

IMAP4 protocol is different with POP3 protocol. First of all, IMAP4 supports retrieving email from different mail folder and folder management. Secondly, IMAP4 supports mail flags management. Therefore, we can do more things with IMAP4 server. To better understand the IMAP4 protocol, please see the following examples.

Note

Remarks: All of examples in this section are based on first section: A simple C++/CLI/CLR project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference to your project.

[C++/CLI/CLR Example - Retrieve email from IMAP4 inbox]

The following example codes demonstrate how to download email from IMAP4 server default mailbox. In order to run it correctly, please change email server, user, password, folder, file name values.

Note

To get the full sample projects, please refer to Samples section.

#include "stdafx.h"

using namespace System;
using namespace System::Globalization;
using namespace System::IO;
using namespace EAGetMail; //add EAGetMail namespace

// Generate an unqiue email file name based on date time
static String ^ _generateFileName(int sequence)
{
    DateTime currentDateTime = DateTime::Now;
    return String::Format("{0}-{1:000}-{2:000}.eml",
        currentDateTime.ToString("yyyyMMddHHmmss", gcnew CultureInfo("en-US")),
        currentDateTime.Millisecond,
        sequence);
}

int main(array<System::String ^> ^args)
{
    try
    {
        // Create a folder named "inbox" under current directory
        // to save the email retrieved.
        String ^localInbox = String::Format("{0}\\inbox", Directory::GetCurrentDirectory());

        // If the folder is not existed, create it.
        if (!Directory::Exists(localInbox))
        {
            Directory::CreateDirectory(localInbox);
        }

        MailServer ^oServer = gcnew MailServer("imap.emailarchitect.net",
            "test@emailarchitect.net",
            "testpassword",
            ServerProtocol::Imap4);

        // Enable SSL/TLS connection, most modern email server require SSL/TLS by default
        oServer->SSLConnection = true;
        oServer->Port = 993;

        // if your server doesn't support SSL/TLS, please use the following codes
        // oServer->SSLConnection = false;
        // oServer->Port = 143;

        Console::WriteLine("Connecting server ...");

        MailClient ^oClient = gcnew MailClient("TryIt");
        oClient->Connect(oServer);

        array<MailInfo^> ^infos = oClient->GetMailInfos();
        Console::WriteLine("Total {0} email(s)\r\n", infos->Length);

        for (int i = 0; i < infos->Length; i++)
        {
            MailInfo ^info = infos[i];
            Console::WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
                info->Index, info->Size, info->UIDL);

            // Generate an unqiue email file name based on date time
            String^ fileName = _generateFileName(i + 1);
            String^ fullPath = String::Format("{0}\\{1}", localInbox, fileName);

            // Receive email from IMAP server
            Mail ^oMail = oClient->GetMail(info);
            Console::WriteLine("From: {0}", oMail->From->ToString());
            Console::WriteLine("Subject: {0}\r\n", oMail->Subject);

            // Save email to local disk
            oMail->SaveAs(fullPath, true);

            // Mark email as deleted from IMAP server.
            oClient->Delete(info);
        }

        // Quit and expunge emails marked as deleted from IMAP server.
        oClient->Quit();
        Console::WriteLine("Completed!");
    }
    catch (Exception ^ep)
    {
        Console::WriteLine(ep->Message);
    }

    return 0;
}

Because IMAP4 protocol supports folder access, so we can retrieve email from other mailbox rather than default “INBOX”. POP3 protocol doesn’t support this feature.

[C++/CLI/CLR Example - Retrieve email from “Deleted Items”]

The following example codes demonstrate how to retrieve emails from “Deleted Items” in an IMAP4 account. In order to run it correctly, please change email server, user, password, folder, file name values.

Note

To get the full sample projects, please refer to Samples section.

#include "stdafx.h"

using namespace System;
using namespace System::Globalization;
using namespace System::IO;
using namespace EAGetMail; //add EAGetMail namespace

// if you want to search sub folder, use parentfolder\\subfolder as folderPath
// for example: inbox\\mysubfolder
Imap4Folder^ FindFolder(String^ folderPath, array<Imap4Folder^> ^folders)
{
    for (int i = 0; i < folders->Length; i++)
    {
        Imap4Folder^ folder = folders[i];

        // Folder was found.
        if (String::Compare(folder->LocalPath, folderPath, true) == 0)
            return folder;

        folder = FindFolder(folderPath, folder->SubFolders);
        if (folder != nullptr)
            return folder;
    }

    // No folder found
    return nullptr;
}

// Generate an unqiue email file name based on date time
static String ^ _generateFileName(int sequence)
{
    DateTime currentDateTime = DateTime::Now;
    return String::Format("{0}-{1:000}-{2:000}.eml",
        currentDateTime.ToString("yyyyMMddHHmmss", gcnew CultureInfo("en-US")),
        currentDateTime.Millisecond,
        sequence);
}

int main(array<System::String ^> ^args)
{
    try
    {
        // Create a folder named "inbox" under current directory
        // to save the email retrieved.
        String ^localInbox = String::Format("{0}\\inbox", Directory::GetCurrentDirectory());

        // If the folder is not existed, create it.
        if (!Directory::Exists(localInbox))
        {
            Directory::CreateDirectory(localInbox);
        }

        MailServer ^oServer = gcnew MailServer("imap.emailarchitect.net",
            "test@emailarchitect.net",
            "testpassword",
            ServerProtocol::Imap4);

        // Enable SSL/TLS connection, most modern email server require SSL/TLS by default
        oServer->SSLConnection = true;
        oServer->Port = 993;

        // if your server doesn't support SSL/TLS, please use the following codes
        // oServer->SSLConnection = false;
        // oServer->Port = 143;

        Console::WriteLine("Connecting server ...");

        MailClient ^oClient = gcnew MailClient("TryIt");
        oClient->Connect(oServer);

        // find folder
        Imap4Folder ^ folder = FindFolder("Deleted Items", oClient->GetFolders());
        if (folder == nullptr)
        {
            throw gcnew Exception("Folder not found!");
        }

        // select dest folder
        oClient->SelectFolder(folder);

        array<MailInfo^> ^infos = oClient->GetMailInfos();
        Console::WriteLine("Total {0} email(s)\r\n", infos->Length);

        for (int i = 0; i < infos->Length; i++)
        {
            MailInfo ^info = infos[i];
            Console::WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
                info->Index, info->Size, info->UIDL);

            // Generate an unqiue email file name based on date time
            String^ fileName = _generateFileName(i + 1);
            String^ fullPath = String::Format("{0}\\{1}", localInbox, fileName);

            // Receive email from IMAP server
            Mail ^oMail = oClient->GetMail(info);
            Console::WriteLine("From: {0}", oMail->From->ToString());
            Console::WriteLine("Subject: {0}\r\n", oMail->Subject);

            // Save email to local disk
            oMail->SaveAs(fullPath, true);

            // Mark email as deleted from IMAP server.
            oClient->Delete(info);
        }

        // Quit and expunge emails marked as deleted from IMAP server.
        oClient->Quit();
        Console::WriteLine("Completed!");
    }
    catch (Exception ^ep)
    {
        Console::WriteLine(ep->Message);
    }

    return 0;
}

TLS 1.2

TLS is the successor of SSL, more and more Email servers require TLS 1.2 encryption now.

If your operating system is Windows XP/Vista/Windows 7/Windows 2003/2008/2008 R2/2012/2012 R2, and you got connection error with SSL/TLS connection, you need to enable TLS 1.2 protocol in your operating system like this:

Enable TLS 1.2 on Windows XP/Vista/7/10/Windows 2008/2008 R2/2012

Next Section

At next section I will introduce how to retrieve email from Exchange Server with Web Service protocol.

Appendix

Comments

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