don't open ics file in message

[SergiiBondarenko1990]

PostmarkMessage message;
message.Attachments.Clear();
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(strICSData);
message.AddAttachment(bytes , "meeting.ics", "text/calendar");
var client = new PostmarkClient("")
var sendResult = await client.SendMessageAsync(message);

in OutLook message added .ics file but file should be open in calendar