Paypal api – How to reliably delete message from gmail? [ActiveUp.Net.Mail]

I wrote a programm reading specific messages from gmail. After reading and analysing I want to delete them. However, I can’t get it to work. I use the following code:

    /// <summary>
    /// Deletes a set of E-Mails by their messageID from a given mailbox
    /// </summary>
    /// <param name="messageIds">The IDs of the messages to delete</param>
    /// <param name="mailBox">The mailbox to delete the messages from</param>
    public void DeletMails(List<int> messageIds, string mailBox)
    {
        if (messageIds.Count<1)
        {
            return;
        }
        // get the mailbox
        Mailbox mails = Client.SelectMailbox(mailBox);
        
        // create a collection of flags to set for the emails
        var flags = new FlagCollection();
        // set only the deleted flag
        flags.Add(new Flag("DELETED"));

        Logging.Log.Info($"Deleting {messageIds.Count} mails");
        // set the flag for each email in the messageIds
        try
        {
            foreach (var id in messageIds)
            {
                mails.DeleteMessage(id, true);
                mails.SetFlags(id, flags);
            }
        }
        catch (Exception ex)
        {
            Logging.Log.Error($"{ex.Message}:{ex.StackTrace}");
        }

        Logging.Log.Info($"Finished deleting {messageIds.Count} mails");

        Client.Expunge();
        Client.Disconnect();
    }

I know there mey be some duplicates in the code

• mails.DeleteMessage(id, true);
• mails.SetFlags(id, flags);
• Client.Expunge();

However. It does not work.

When I log into my gmail account, I can still see the emails. Only change: they are marked as read and the label is removed from them. (Example: I label each email from [email protected] with the label PayPal using the filter settings of gmail, then I get all the emails from the mailbox PayPal and remember their ID and delete them. After that they are marked as read and they no longer have the label PayPal, but they are not deleted from the mailbox PayPal.)

There is no exception thrown when executing the code.

Any idea why? Do you recommend using another Mail-API? I am using ActiveUp.Net.Mail.

Thanks for your advice.