MailMessage Delete attachments after sending if in Path.GetTempPath()

Question

Pardon my newness to the MailMessage and SmtpClient classes. I've built something that basically works, but in preparing to send the attachments, I sometimes copy the attachments to the temporary files location (Path.GetTempPath() + @"\" + timestampWithFF), because they sometimes must be zipped to send. When this happens, I want to make sure I delete the files there after sending (especially because anything there is going to be relatively large).

Two-fold question: 1. should I not bother with cleaning up the files because the OS (win7) will do a good job of it? 2. how can I get the HDD location of the Attachments in client.SendCompleted?

client.SendCompleted += (s, e) =>
{
    client.Dispose();
    foreach(Attachment a in msg.Attachments)
    {
        // want to actually delete the file from the HDD if it's in Path.GetTempPath();
    }
    msg.Dispose();
};

I see I could use a.Dispose(), but I don't have any idea what it does...I suspect it's disposing of the object (which msg.Dispose would do next anyways), but would leave the files on the HDD.

must I send the filepaths of the attachments separately? the client.SendCompleted() line is in: sendMailAsync(SmtpClient client, MailMessage msg) method. I could change this to: sendMailAsync(SmtpClient client, MailMessage msg, List<string> attachments) and add this to the SendCompleted(), but it feels kinda clunky:

string tempDir = Path.GetTempPath();
foreach(string f in attachments)
{
    if(f.Contains(tempDir))    // want to actually delete the file from the HDD if it's in Path.GetTempPath();
    {
        if (File.Exists(f)) { File.Delete(f); }
    }
}

Answer 1

1. should I not bother with cleaning up the files because the OS (win7) will do a good job of it?

If i were you, I would still delete the temp file, though OS would clean it, when it deems necessary

2. how can I get the HDD location of the Attachments in client.SendCompleted?

The files in the attachments can be retrieved through ContentStream. Their type would be of FileStream.

client.SendCompleted += (s, e) =>
{
    client.Dispose();
    var fileattachments = msg.Attachments
                          .Select(x => x.ContentStream)
                          .OfType<FileStream>()
                          .Select(fs => fs.Name)
                          .ToArray();

    msg.Dispose();

    string tempPath = Path.GetTempPath();
    foreach (var attachment in fileattachments )
    {
        if(attachment.Contains(tempPath)
        {
            File.Delete(attachment);
        }

    }
};

Note: First dispose the msg object and then do the deletion