Searching the inbox and its sub folders is not that difficult, but I fail to see the point of searching sent, draft, & outbox; and replies to sent or outbox messages would go to you.
The following should get you started
Option Explicit
'Graham Mayor - https://www.gmayor.com - Last updated - 18 Jun 2020
Private Const sSubject As String = '"The text to find"
Sub ProcessFolders()
Dim cFolders As Collection
Dim olFolder As Outlook.Folder
Dim SubFolder As Folder
Dim olNS As Outlook.NameSpace
On Error Resume Next
Set cFolders = New Collection
Set olNS = GetNamespace("MAPI")
cFolders.Add olNS.PickFolder
Do While cFolders.Count > 0
Set olFolder = cFolders(1)
cFolders.Remove 1
FindSubject olFolder
For Each SubFolder In olFolder.folders
cFolders.Add SubFolder
Next SubFolder
Loop
lbl_Exit:
Set olFolder = Nothing
Set SubFolder = Nothing
Exit Sub
err_Handler:
GoTo lbl_Exit
End Sub
Private Sub FindSubject(iFolder As Folder)
Dim olItem As Outlook.MailItem
Dim olMsg As Outlook.MailItem
Dim i As Long
iFolder.items.Sort "[Received]", True
For i = iFolder.items.Count To 1 Step -1
Set olItem = iFolder.items(i)
If TypeName(olItem) = "MailItem" Then
If InStr(1, olItem.Subject, sSubject) > 0 Then
Debug.Print olItem.Subject & vbTab & olItem.sender
Set olMsg = olItem.ReplyAll
olMsg.Display
'do stuff with olMsg
Exit For
End If
End If
Next i
lbl_Exit:
Set olItem = Nothing
Exit Sub
End Sub