From MozillaZine Knowledge Base
The FTP specification dictates that users must give a username and a password when logging in to a server. If a server allows anonymous logins, clients usually log in with the username “anonymous” and a password corresponding to an email address. This preference lets you determine whether to use the default “firstname.lastname@example.org” as the password, or to send the contents of the preference network.ftp.anonymous_password.
Possible values and their effects
Send the value of network.ftp.anonymous_password as the password for anonymous logins.
Send “email@example.com” as the password for anonymous logins. (Default)
A checkbox labeled “Send email address as anonymous FTP password” is located under “Edit → Preferences → Advanced”.
Originally, setting this preference to true would cause Mozilla to use the email address from the mail client portion of the application suite.
First checked in
Present since at least 1999-06-04. Exact checkin date unknown.
Has an effect in