Gets the flags that are applicable for the currently selected folder.
A reference to the MessageFlagSet object representing the flags that are applicable for the currently selected folder.
If the folder is selected, the flag list contains the system-defined flags at a minimum (except "\Recent" flag which cannot be edited by the client). Typically, the following flags are returned: "\Answered", "\Flagged", "\Deleted", "\Seen", "\Draft". Also, this list may contain other flags specific to certain servers (like "$Spam", "$Personal", etc).
If no folder is selected, the flag list will be empty.
To access the flag list as a string, the developer can use ToString method. To access the system-defined flags of the flag list, the SystemFlags property can be used.
Imap Class | MailBee.ImapMail Namespace