If we have a custom list named "Testing" and have an item which has multiple attachments. if we  need to send all those attachments in an email then follow below steps:
Steps Involved:
- Open Visual Studio 2010 by going Start | All Programs | Microsoft Visual Studio 2010 | Right click on Microsoft Visual Studio 2010 and click on Run as administrator.
 - Go to File tab, click on New and then click on Project.
 - In the New Project dialog box, expand the Visual C# node, and then select the Windows node.
 - In the Templates pane, select Console Application.
 -  Enter the Name as SendEmail and then click OK.
 -  In the solution explorer, right click on the solution and then click on Properties.
 - Select the Application tab; check whether “.Net Framework 3.5” is selected for TargetFramework.
 - Select the Build tab; check whether “Any CPU” is selected for Platform Target.
 - Add the following references
 
a)      Microsoft.SharePoint    
- Add the following namespaces
 
a)      using Microsoft.SharePoint; 
b)      using System.Net.Mail;
- Replace Program.cs with the following code
 
  | 
This code will send email with attachments you want to send.