(PowerShell) Reading Unread POP3 Email

The POP3 protocol does not provide the ability to ask the server which emails are "unread". Furthermore, a pure POP3 server does not even keep this information. Some servers, such as Exchange Server, expose both POP3 and IMAP interfaces. In these cases, information about read/unread status exists on the server, but it is only available via the IMAP protocol. Email clients such as Outlook and Thunderbird keep read/unread information on the client computer. This example demonstrates how UIDLs can be saved to track and read "unread" email.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This example requires 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.
$mailman = New-Object Chilkat.MailMan

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

# Set the POP3 login/password.
$mailman.PopUsername = "***"
$mailman.PopPassword = "***"

# You may keep a list of already-seen UIDLs in a text file:
# If this is the first time you're running this example,
# create an empty text file named "seenUidls.txt"
$saSeenUidls = New-Object Chilkat.StringArray
$success = $saSeenUidls.LoadFromFile("seenUidls.txt")
if ($success -ne $true) {
    $("failed to load seenUidls.txt")
    exit
}

# Get the complete list of UIDLs on the mail server.
$saUidls = $mailman.GetUidls()
if ($mailman.LastMethodSuccess -eq $false) {
    $($mailman.LastErrorText)
    exit
}

# Create a new string array object (it's an object, not an actual array)
# and add the UIDLs from saUidls that aren't already seen.
$saUnseenUidls = New-Object Chilkat.StringArray

$i = 0
$n = $saUidls.Count
while ($i -lt $n) {
    if ($saSeenUidls.Contains($saUidls.GetString($i)) -ne $true) {
        $success = $saUnseenUidls.Append($saUidls.GetString($i))
    }

    $i = $i + 1
}

if ($saUnseenUidls.Count -eq 0) {
    $("No unseen emails!")

    exit
}

# Download in full the unseen emails:
$bundle = $mailman.FetchMultiple($saUnseenUidls)
if ($mailman.LastMethodSuccess -eq $false) {
    $($mailman.LastErrorText)

    exit
}

$i = 0
while ($i -lt $bundle.MessageCount) {
    $email = $bundle.GetEmail($i)
    $($email.From)
    $($email.Subject)
    $("----")

    $i = $i + 1
}

# Save saUidls to "seenUidls.txt"
$success = $saUidls.SaveToFile("seenUidls.txt")