Created Unassigned: Imapx Need to be Thread Safe! [2795]

Hi,

__When invoking Flags.Add(..) or some other action such as Folder.Search() or MoveTo, A NotSupportedException is raised on SSLStream.ProcessRead()...__

```
System.dll!System.Net.Security._SslStream.ProcessRead Normal
System.dll!System.Net.Security._SslStream.ProcessRead(byte[] buffer = {byte[1024]}, int offset = 0, int count = 1024, System.Net.AsyncProtocolRequest asyncRequest = null)
System.dll!System.Net.Security._SslStream.Read(byte[] buffer = {byte[1024]}, int offset = 0, int count = 1024)
System.dll!System.Net.Security.SslStream.Read(byte[] buffer = {byte[1024]}, int offset = 0, int count = 1024)
mscorlib.dll!System.IO.StreamReader.ReadBuffer()
mscorlib.dll!System.IO.StreamReader.ReadLine()
ImapX.dll!ImapX.ImapBase.SendAndReceive(string command = "EXAMINE \"INBOX\"", ref System.Collections.Generic.IList<string> data = Count = 0, ImapX.Parsing.CommandProcessor processor = null, System.Text.Encoding encoding = null, bool pushResultToDatadespiteProcessor = false)
ImapX.dll!ImapX.Folder.Examine()
ImapX.dll!ImapX.Folder.SearchMessageIds(string query = "UNFLAGGED", int count = 10)
ImapX.dll!ImapX.Folder.Search(string query = "UNFLAGGED", ImapX.Enums.MessageFetchMode mode = -1, int count = 10)
```

```
ImapX.dll!ImapX.ImapBase.StopIdling Normal
mscorlib.dll!System.Threading.Thread.Join()
ImapX.dll!ImapX.ImapBase.StopIdling(bool pausing = false)
ImapX.dll!ImapX.Folder.Select()
ImapX.dll!ImapX.Collections.MessageFlagCollection.AddRange(System.Collections.Generic.IEnumerable<string> flags = {string[1]})
ImapX.dll!ImapX.Collections.MessageFlagCollection.Add(string flag = "\\Seen")
```