(VB.NET UWP/WinRT) POP3: Download Most Recent Email (method 1)

How to ready the N most recent email from a POP3 server.

The POP3 protocol does not provide the ability to request the most recent email, nor does it provide the ability to download email based on read/unread status or any other criteria. The design principle behind POP3 is that it is a temporary holding store for incoming email and email clients or other applications will transfer email from the POP3 server to a local persistent store where it will be managed. Therefore, POP3 does not provide sophisticated functionality (as opposed to IMAP which has the opposite design philosophy: that email is maintained and organized on the server).

This example shows one possible way to retrieve the N most recent emails from a POP3 server. It downloads the headers into a bundle object, then sorts the bundle by date, and finally retrieves the most recent emails by UIDL.

Another alternative is to download the UIDL list and then assume that the 1st N UIDLs are the most recent.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' The mailman object is used for receiving (POP3) 
' and sending (SMTP) email.
Dim mailman As New Chilkat.MailMan
Dim success As Boolean

' Set the POP3 server's hostname
mailman.MailHost = "pop.someMailServer.com"

' Set the POP3 login/password.
mailman.PopUsername = "myLogin"
mailman.PopPassword = "myPassword"

' Read mail headers and one line of the body.
Dim bundle As Chilkat.EmailBundle = Await mailman.GetAllHeadersAsync(1)
If (mailman.LastMethodSuccess = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


' Sort the bundle by date
Dim ascending As Boolean = False
bundle.SortByDate(ascending)

' Get the 10 most recent UIDLs
Dim saUidls As New Chilkat.StringArray
Dim n As Integer = bundle.MessageCount
If (n > 10) Then
    n = 10
End If


Dim i As Integer = 0
Dim email As Chilkat.Email
While i < n
    email = bundle.GetEmail(i)
    success = saUidls.Append(email.Uidl)


    i = i + 1
End While



' Download in full the 10 most recent emails:
Dim bundle2 As Chilkat.EmailBundle = Await mailman.FetchMultipleAsync(saUidls)
If (mailman.LastMethodSuccess = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


i = 0
While i < bundle2.MessageCount
    email = bundle2.GetEmail(i)
    Debug.WriteLine(email.From)
    Debug.WriteLine(email.Subject)
    Debug.WriteLine("----")


    i = i + 1
End While