Create a custom file attachment for an email from a string

Question

What I want to do is to create a mail attachment from a string file and give it my own custom extension.

    public void CreateAttachment(string encryptedString, string fileName)
    {
        mail.Attachments.Add(Attachment.CreateAttachmentFromString(encryptedString, fileName));
    }

I want to create a ".bzk" file and it's gonna be opened in a mobile Android application later. How do I do this? I know there are different constructors as you can see here!

I do not know what constructors I have to use and even after trying different MIME types and Encodings, it won't work. Can anyone tell me how to do this?

edit:

I've solved my problem. Here is my solution:

public void CreateAttachment(string encryptedString, string fileName)
    {
        MemoryStream ms = new MemoryStream(
            ASCIIEncoding.ASCII.GetBytes(encryptedString)
        );

        Attachment attachment = new Attachment(ms, new ContentType("text/bzk"));
        attachment.Name = fileName + ".bzk";

        mail.Attachments.Add(attachment);

    }

Answer 1

I've solved my problem. Here is my solution:

public void CreateAttachment(string encryptedString, string fileName)
{
    MemoryStream ms = new MemoryStream(
        ASCIIEncoding.ASCII.GetBytes(encryptedString)
    );

    Attachment attachment = new Attachment(ms, new ContentType("text/bzk"));
    attachment.Name = fileName + ".bzk";

    mail.Attachments.Add(attachment);
}