(Swift) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // 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.
    let mailman = CkoMailMan()!

    // 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"
    let saSeenUidls = CkoStringArray()!
    var success: Bool = saSeenUidls.load(fromFile: "seenUidls.txt")
    if success != true {
        print("failed to load seenUidls.txt")
        return
    }

    // Get the complete list of UIDLs on the mail server.
    var saUidls: CkoStringArray? = mailman.getUidls()
    if mailman.lastMethodSuccess == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    // 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.
    let saUnseenUidls = CkoStringArray()!

    var i: Int = 0
    var n: Int = saUidls!.count.intValue
    while i < n {
        if saSeenUidls.contains(saUidls!.getString(i)) != true {
            success = saUnseenUidls.append(saUidls!.getString(i))
        }

        i = i + 1
    }

    if saUnseenUidls.count.intValue == 0 {
        print("No unseen emails!")
        saUidls = nil
        return
    }

    // Download in full the unseen emails:
    var bundle: CkoEmailBundle? = mailman.fetchMultiple(saUnseenUidls)
    if mailman.lastMethodSuccess == false {
        print("\(mailman.lastErrorText!)")
        saUidls = nil
        return
    }

    var email: CkoEmail?
    i = 0
    while i < bundle!.messageCount.intValue {
        email = bundle!.getEmail(i)
        print("\(email!.from!)")
        print("\(email!.subject!)")
        print("----")
        email = nil
        i = i + 1
    }

    // Save saUidls to "seenUidls.txt"
    success = saUidls!.save(toFile: "seenUidls.txt")

    saUidls = nil

}