Cone is distributed in source code form, licensed under GPL. See COPYING for more information. The following prerequisites must be installed to build and run Cone:
A wide-character version of the curses library. ncurses supports wide characters starting with version 5.3, if enabled at compile time.
Libidn; although Cone will compile without it, internationalized domain names will not be shown properly.
Cone optionally supports LDAP address books. LDAP support requires OpenLDAP.
It is not sufficient to have only the OpenLDAP
runtime libraries installed. The OpenLDAP development
kit must be installed as well. On most systems it's
usually called the "devel" component, that must be
installed in addition to the base OpenLDAP component.
Verify that the /usr/include/ldap.h file exist,
before trying to build Cone. If not, the required
OpenLDAP development libraries are missing, and must be
installed.
LDAP-based address books are highly recommended for corporate and organizational environments. Cone's basic address books (local address books and IMAP/SMAP folder-based address books) have somewhat limited search functionality -- addresses are looked up by exact nicknames only. LDAP-based address books are more powerful, they may be searched not just by exact nicknames, but also by last name or full names. Partial searches are also possible.
The current version of the gcc compiler
gmake (if not already installed)
The Courier Socks 5 proxy client API toolkit is required for Socks 5 support. Other Socks 5 proxy client libraries may or may not work. Download the Courier Socks 5 proxy client library from https://www.courier-mta.org/download.php#sox and follow its installation instructions.
Right now the primary development focus is on the Linux platform, but Cone should build on other POSIX platforms; and any problems are likely to be minor, and trivial to resolve. A large portion of Cone's code base comes from Courier, which builds on many platforms.
Cone requires a wide-character-capable version of Curses. Cone will compile against a non-widechar Curses, but will not be able to display UTF-8, or other variable-length character sets.
Cone reads local mail
from either maildirs (the preferred format) or mailbox files
(or "mboxes"). When mboxes are used, Cone does not read the system mailbox
file directly (usually /var/spool/). All
messages in the system mailbox are automatically moved to
something$HOME/Inbox, which is then
accessed as if it was the system mailbox. Starting
Cone for the first time on
an mbox-based system automatically copies all existing mail
from the system mailbox file to $HOME/Inbox.
This is an intentional design choice. Normal user
application cannot create new files in /var/spool; all they can do is read the
mailbox file from /var/spool.
Therefore, the only way to update the mailbox file is by
rewriting it from scratch (more or less). While the mailbox
file is in the process of being rewritten, if the
Cone process is interrupted,
or killed, the resulted in a corrupted system mailbox. There
are way to minimize this vulnerability, but it cannot be
eliminated completely. Some Linux kernels use an “OOM killer” that
may terminate any process when the system memory is low.
There is no way to completely prevent corrupted system
mailbox files on those kernels.
Cone uses an alternative
way of updating mboxes. Cone
updates mboxes by creating a new mbox file separately, then
replacing the original mbox file with the new version.
Unfortunately this cannot be done with the system mailbox
file, because of the restricted access rights on the system
spool directory. To solve this problem Cone automatically copies the system
mailbox file to $HOME/Inbox,
each time the system mailbox file is opened and whenever new
mail is available.