Drop Box Password:

The recipient of a message that is sent using Safe-mail Secure Drop-Box can access the message using a password. By default, the password is taken from the recipient's contact card in the sender's address book. Read further for more details.

A password that is entered in the recipient's contact card in your address book.
Any message sent to this recipient is protected automatically using that password. This option is recommended since it allows you to set a unique and convenient personal password for that recipient and it eliminates the need to provide the password every time a message is sent to that recipient that do not have personal password. (How to add a password in the contact card?)

If the 'Drop-Box Password' field in the recipient's contact card is empty, or if there is no contact card for that recipient in your address book, there are several alternate options for an alternate password:

• Use the following default password:
  This option allows you to set a default password to all your Drop-Box recipients that do not have personal password. This is a convenient way to add security to outgoing messages, though it is not totally secure since all the recipients use the same password in order to access their messages.
• Use an automatically generated random password.
  The Safe-mail server generates a random password and attaches it to the notification that is sent to the recipient. Although it is not secure since the password is sent using a non-secure message, this option allows you to receive a read confirmation of the recipient.