IMail | 
public static Task SetFlagsAsync( this IMailFolder folder, int index, MessageFlags flags, HashSet<string> keywords, bool silent, CancellationToken cancellationToken = default )
| Exception | Condition | 
|---|---|
| ArgumentException | index is invalid. | 
| ObjectDisposedException | The IMailStore has been disposed. | 
| ServiceNotConnectedException | The IMailStore is not connected. | 
| ServiceNotAuthenticatedException | The IMailStore is not authenticated. | 
| FolderNotOpenException | The folder is not currently open in read-write mode. | 
| OperationCanceledException | The operation was canceled via the cancellation token. | 
| IOException | An I/O error occurred. | 
| ProtocolException | The server's response contained unexpected tokens. | 
| CommandException | The command failed. |