Gets the next UID value to be assigned to a new message.
The positive 32-bit Int64 value containing the next UID value of the folder, or -1 if this information is not available.
This is the UID value which will be assigned to a new message when it's gets placed to the folder. UidNext value conforms the following conditions: first, the next UID value WILL NOT change unless new messages are added to the mailbox; and second, the next UID value WILL change whenever new messages are added to the folder, even if those new messages are subsequently expunged.
FolderStatus Class | MailBee.ImapMail Namespace