VB.NET

Download the Full Version of a Partial Email

Demonstrates the Chilkat MailMan.FetchFull method, which downloads the complete version of a header-only or partial Email and stores it in a second Email. The full result includes the complete body and any attachments, and the partial email must retain its UIDL. This example previews message 1 (headers only) and then downloads it in full.

Background: A common pattern is to download headers first — cheap and fast — show the user a message list, and only pull the full content when a message is actually opened. FetchFull completes that "download on demand" flow: given a partial email (which carries its UIDL), it fetches the rest from the server. This keeps bandwidth and latency low when browsing a large mailbox.

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Dim success As Boolean = False

'  Demonstrates the MailMan.FetchFull method, which downloads the complete version of a
'  header-only or partial Email and stores it in a second Email.  The full result includes
'  the complete body and any attachments.  The partial email must retain its UIDL.

Dim mailman As New Chilkat.MailMan

'  Configure the POP3 server connection.
mailman.MailHost = "pop.example.com"
mailman.MailPort = 995
mailman.PopSsl = True
mailman.PopUsername = "user@example.com"
mailman.PopPassword = "myPassword"

'  First fetch message 1 as headers only (a fast preview).  headerOnly=True.
Dim partialEmail As New Chilkat.Email

success = mailman.FetchOne(True,0,1,partialEmail)
If (success = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If

Debug.WriteLine("Preview subject: " & partialEmail.Subject)

'  Now download the complete message (body and attachments).
Dim fullEmail As New Chilkat.Email
success = mailman.FetchFull(partialEmail,fullEmail)
If (success = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If

Debug.WriteLine("Full email NumAttachments: " & fullEmail.NumAttachments)

'  Note: Explicitly connecting/authenticating is optional.  Chilkat MailMan automatically
'  connects and authenticates -- using the property settings above -- whenever a server
'  operation requires it.  Calling the explicit connect/authenticate methods can still be
'  helpful to determine whether a failure occurs while connecting or while authenticating.