Read and save Attachment from Outlook using C# and VB.Net in ASP.Net

Hi rakibxl,

Refer below code.

Namespaces

C#

using Outlook = Microsoft.Office.Interop.Outlook;

VB.Net 

Imports Outlook = Microsoft.Office.Interop.Outlook

Code

C#

public void EnumerateFolders(Outlook.Folder folder)
{
    Outlook.Folders childFolders = folder.Folders;
    if (childFolders.Count > 0)
    {
        foreach (Outlook.Folder childFolder in childFolders)
        {
            if (childFolder.FolderPath.Contains("Inbox"))
            {
                IterateMessages(childFolder, Server.MapPath("~/Attachments/"));
                EnumerateFolders(childFolder);
            }
        }
    }
}

public void IterateMessages(Outlook.Folder folder, string pathToSaveFile)
{
    var fi = folder.Items;
    if (fi != null)
    {
        foreach (Object item in fi)
        {
            Outlook.MailItem mi = (Outlook.MailItem)item;
            var attachments = mi.Attachments;
            if (attachments.Count != 0)
            {
                for (int i = 1; i <= mi.Attachments.Count; i++)
                {
                    string[] extensionsArray = { ".txt" };
                    if (extensionsArray.Any(mi.Attachments[i].FileName.Contains))
                    {
                        mi.Attachments[i].SaveAsFile(pathToSaveFile + mi.Attachments[i].FileName);
                    }
                }
            }
        }
    }
}

VB.Net

Public Sub EnumerateFolders(ByVal folder As Outlook.Folder)
    Dim childFolders As Outlook.Folders = folder.Folders
    If childFolders.Count > 0 Then
        For Each childFolder As Outlook.Folder In childFolders
            If childFolder.FolderPath.Contains("Inbox") Then
                IterateMessages(childFolder, Server.MapPath("~/Attachments/"))
                EnumerateFolders(childFolder)
            End If
        Next
    End If
End Sub

Public Sub IterateMessages(ByVal folder As Outlook.Folder, ByVal pathToSaveFile As String)
    Dim fi = folder.Items
    If fi IsNot Nothing Then
        For Each item As Object In fi
            Dim mi As Outlook.MailItem = CType(item, Outlook.MailItem)
            Dim attachments = mi.Attachments
            If attachments.Count <> 0 Then
                For i As Integer = 1 To mi.Attachments.Count
                    Dim extensionsArray As String() = {".txt"}
                    If System.IO.Path.GetExtension(mi.Attachments(i).FileName).ToLower() = ".txt" Then
                        mi.Attachments(i).SaveAsFile(pathToSaveFile & mi.Attachments(i).FileName)
                    End If
                Next
            End If
        Next
    End If
End Sub