I'm not sure what the "loan" function is, but you can have Access examine the Expire date and send an email:

Dim rst As ADODB.Recordset
Dim strBody As String

Set rst = New ADODB.Recordset
rst.Open "SELECT EmailAddress, YourDateField FROM SomeTable WHERE DateDiff("d",  YourExpireDateField, Now) <=1",
CurrentProject.Connection

If Not (rst.EOF and rst.BOF) Then
    '/build the body
    strBody = "Your xxx is set to expire tomorrow. Please renew or else"
    DoCmd.SendObject acSendNoObject, , , rst("EmailAddress"), , , "Expire Notice", strBody
End If

Set rst = Nothing

Scott McDaniel
scott@takemeout_infotrakker.com
www.infotrakker.com