jodd-mail/src/main/java/jodd/mail/ReceiveMailSession.java
public void useFolder(final String folderName) {
		closeFolderIfOpened(folder);

		try {
			this.folderName = folderName;
			this.folder = getService().getFolder(folderName);
			try {
				folder.open(Folder.READ_WRITE);
			} catch (final MailException ignore) {
				folder.open(Folder.READ_ONLY);
			}
		} catch (final MessagingException msgexc) {
			throw new MailException("Failed to connect to folder: " + folderName, msgexc);
		}
	}
public void useFolder(final String folderName) {
		closeFolderIfOpened(folder);

		try {
			this.folderName = folderName;
			this.folder = getService().getFolder(folderName);
			try {
				folder.open(Folder.READ_WRITE);
			} catch (final MailException ignore) {
				folder.open(Folder.READ_ONLY);
			}
		} catch (final MessagingException msgexc) {
			throw new MailException("Failed to connect to folder: " + folderName, msgexc);
		}
	}
Opens new folder and closes previously opened folder.

@param folderName Folder to open