Classic ASP

Get the POP3 UIDL of an Email

Demonstrates the read-only Chilkat Email.Uidl property, which contains the unique message identifier assigned by a POP3 server; the value is also represented by the X-UIDL header field. This example sets X-UIDL directly to illustrate how it maps to the Uidl property (normally the value comes from the POP3 server during download).

Background: A UIDL ("unique ID listing") is POP3's stable identifier for a message in a mailbox — it stays the same across sessions, so a client can remember which messages it has already downloaded and avoid fetching them again. Note this is POP3-specific: IMAP uses its own UID instead, which Chilkat stores in the ckx-imap-uid header rather than in Uidl.

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Classic ASP

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
'  Demonstrates the read-only Email.Uidl property, which contains the unique message
'  identifier assigned by a POP3 server.  The value is represented by the X-UIDL header
'  field.  Here we set X-UIDL directly to show how it maps to the Uidl property.

set email = Server.CreateObject("Chilkat.Email")

'  Normally the POP3 server assigns this; we set it here for demonstration.
email.AddHeaderField "X-UIDL","0000000123abcdef"

Response.Write "<pre>" & Server.HTMLEncode( "Uidl = " & email.Uidl) & "</pre>"

%>
</body>
</html>