For calling this custom form from vb.net form with the help of these lines of code:
Dim outLookApp As New Microsoft.Office.Interop.Outlook.Application() Dim objNameSpace As Microsoft.Office.Interop.Outlook.NameSpace = _ outLookApp.GetNamespace("MAPI") Dim objFolder As Microsoft.Office.Interop.Outlook.MAPIFolder = _ objNameSpace.GetDefaultFolder _ (Microsoft.Office.Interop.Outlook.OlDefaultFolders.olFolderInbox) Dim MailItem As Microsoft.Office.Interop.Outlook.MailItem = _ DirectCast(outLookApp.CreateItem _ (Microsoft.Office.Interop.Outlook.OlItemType.olMailItem), _ Microsoft.Office.Interop.Outlook.MailItem) MailItem = DirectCast(objFolder.Items.Add("IPM.Note.MyApplicationForm"), _ Microsoft.Office.Interop.Outlook.MailItem) MailItem.Display("IPM.Note.MyApplicationForm")
(Need to add Microsoft.Office.Interop.Outlook library referance)