I created a mail in a database that users will use to send scheduled e-mails. I created an action button, a scheduled send and a hidden field scheduled date. When a user clicks scheduled send, a prompt will appear where the user will fill in the date and time of delivery. This doc will be then saved as a draft. A view has been created that captures docs where the scheduled date is not blank. How do I create an agent that will open this view, go to the first document and see if the scheduled date is less then now, send, save and flag the message. How do I flag the message indicating it has been sent? Flagged messages will not show in the view.
I would create a flag field, SendFlag, and when a document is created that is to be sent at a scheduled time, set the field to "NeedToSend." Change your view selection criteria to only select documents where SendFlag = "NeedToSend." Sort the view by date and time so the earliest dates and times are first.

You could have an agent similar to the one below scheduled to run hourly.

Sub Initialize
  Dim s As New NotesSession
  Dim db As NotesDatabase
  Dim view As NotesView
  Dim doc As NotesDocument
  Dim docNext As NotesDocument
  Dim dtNow As New NotesDateTime( "" )
  Dim dtSend As New NotesDateTime( "" )
  Dim item As NotesItem
  Dim intProcess As Integer
  Set db = s.CurrentDatabase
  Set view = "scheduledmailview"
  
  Call dtNow.SetNow
  ' depending on how often your agent will run
  ' add minutes to the current time so it will
  ' include documents scheduled to be sent within
  ' that time period.
  Call dtNow.AdjustMinute( 35 )
  
  Set doc = view.GetFirstDocument
  intProcess = True
  While (intProcess)
    Set item = doc.GetFirstItem( "sendDateTime" )
    Set dtSend = item.DateTimeValue
    If (dtSend < dtNow) Then
      Set item = doc.ReplaceItemValue ( "SendFlag", "Sent" )
      Call doc.Send(False)
      Call doc.Save(True, False)
    Else
      intProcess = False
      EndIF
      Set doc = dc.GetNextDocument(doc)
    Wend
End Sub

This was first published in September 2003