Provided by: prayer_1.3.5-dfsg1-6.1_amd64 
NAME
prayer.cf — main Prayer configuration file
DESCRIPTION
prayer.cf is the configuration file of prayer(8) and prayer-session(8).
SYNTAX
For the most part, prayer.cf consists of option = value pairs, but some configuration items
are more complex. All values may be enclosed in double quotes, which are stripped. Quotes
must be used if a value contains a ‘#’ character. Otherwise, everything following it is
treated as a comment. Any line can be folded using a ‘\’ character at the end of the line;
any linear white space at the beginning of the next line is removed.
Simple options can be of the following types:
string No particular restrictions.
path A file or directory name. The configuration parser expands occurences of a few
macros in settings of this type. See prefix and var_prefix below.
boolean
The following forms are interpreted as true: ‘true’, ‘t’, and ‘1’. The following
forms are interpreted as false: ‘false’, ‘nil’, ‘0’. Capitalisation does not
matter.
number An integer number (sequence of digits 0-9), optionally immediately followed by a
single letter ‘K’, causing the number to be multiplied by 1024, or ‘M’ multiplying
it by 1024 · 1024.
time An integer number (sequence of digits 0-9) of seconds, optionally immediately
followed by a single case-insignificant letter ‘s’, which has no effect, ‘m’,
causing the number to be multiplied by 60, ‘h’, multiplying it by 60 · 60, or ‘d’,
for a multiple of 24 · 60 · 60.
perm A file permission mode; an octal number of exactly four digits, where the first
digit must be 0.
OPTIONS
prefix (string), var_prefix (string)
The values of these options can be referred to as $prefix (or ${prefix}), and
$var_prefix (or ${var_prefix}), respectively, in settings of type path in the rest
of the file.
Default: none. Need to be set only if referenced later.
prayer_user (string), prayer_uid (number)
User name or ID to setuid(2) to if started as root. Either, but not both, must be
set and must not specify uid 0. Default: none.
prayer_group (string), prayer_gid (number)
Group name or ID to setgid(2) to if we start off as root. In addition, prayer calls
initgroups(3) if prayer_user is set. Default: none.
prayer_background (boolean)
Run prayer as background process. If true, prayer will return as soon as valid
configuration is found. Default: true
file_perms (perm)
Create mode for new files. Default: 0640 if prayer_uid or prayer_user is set,
otherwise 0644.
directory_perms (perm)
Create mode for new directories. Default: 0750 if prayer_uid or prayer_user is set,
otherwise 0755.
check_directory_perms (boolean)
Check existing directories under ${var_prefix}?
Mail server settings
imapd_server (string)
Specifies the default IMAP server(s) using libc-client syntax:
host[:port][/flag[/flag]...]
Multiple server specifications can be listed, separated by commas. Common flags are:
/ssl Use SSL-on-connect (on port 993 by default).
/tls Force use of TLS (using STARTTLS on the normal IMAP port) to encrypt the
session. Recommended if the server is remote, since otherwise a downgrade
attack is possible.
/notls Don't issue STARTTLS even if the server supports it. Recommended if the
server is localhost.
/novalidate-cert
Don't check the integrity of the server certificate.
For the full list of flags, see naming.txt.gz in the current libc-client package.
imapd_user_map (path)
CDB lookup map overriding default imapd_server location. For information on CDB, see
• http://cr.yp.to/cdb.html
• http://en.wikipedia.org/wiki/Constant_Data_Base
prefs_folder_name (string)
Name of Prayer user preferences folder on IMAP server.
use_namespace (boolean)
Use IMAP NAMESPACE command to find personal_hierarchy and hiersep. Default: true.
personal_hierarchy (string)
If not supplied by NAMESPACE. Default: "".
hiersep (string)
If not supplied by NAMESPACE. Default: "/".
dualuse (boolean)
Hint to Prayer that new mailboxes are dual use (i.e. can contain both mail and
inferior mailboxes). Things will mostly work if dualuse set to false on a server
which supports it, but people will be unable to create children of newly created
mailboxes without refreshing the view.
Default: false.
sieved_server (string)
Talk to Cyrus timsieved using MANAGESIEVE protocol. Syntax is similar to
imapd_server, except the only recognised flag is /ssl.
sieved_user_map (path)
Can be used to provide individualised imapd_server settings in the form of a CDB
file.
sieved_timeout (time)
Default timsieved timeout is 10 minutes
Mail domain configuration
local_domain
Define a valid local domain, and optionally the valid local parts in that domain.
This is a special directive that can appear multiple times and does not use an
equals sign:
local_domain domain [map]
Without map, local_domain simply defines a domain which will appear on the list
visible to user preferences. With map, it also defines a list a CDB map file which
defines valid entries in that domain; used for personal name expansion and checking
for valid addresses: The keys are the valid local parts and the values are the
corresponding full names of the users.
Default: A single entry which corresponds to default_domain.
return_path_domain (string)
Domain used in the return address given to sendmail(8). Default: the default
domain.
filter_domain_pattern (string)
A filter pattern which is equivalent to, or at least approximates the list of local
domains. Default: the default domain.
hostname (string)
Hostname is the canonical name for this particular system, used in session and icon
URLs which are generated by Prayer. This is derived automatically using
gethostname(2) and gethostbyname(3) if no value is provided. However, there are
situations, especially involving SSL certificates, where the default hostname may
not be appropriate. The special value ‘__UNDEFINED__’ here means the startup script
or command line must provide a hostname using a --config-option override or via the
environment variable PRAYER_HOSTNAME. This is just a safeguard for systems which
use DNS round robining to distribute load across a number of machines.
hostname_service (string)
Host name common for all Prayer installations part of the same webmail service.
(Only) useful for large installations using DNS round robin for load balancing
(example: webmail.hermes.cam.ac.uk is an alias for webmail[123].hermes.cam.ac.uk).
This setting is used for two things: The user is redirected to this hostname after
logging out, and HTTP requests are sanity checked against it in addition to the
canonical hostname.
Default: none
fix_from_address (boolean)
suppresses the From address option from the Preferences and Roles screens. Default:
false.
lookup_rpasswd (path)
Path to a CDB file that maps arbitrary search keys to colon- or comma-separated
lists of user names. Note: Keys must be lowercase; Prayer converts search strings
to lowercase in order to provide case-insensitive lookup.
lookup_rusername (path)
Path to a second CDB file that maps arbitrary search keys to colon- or comma-
separated lists of user names.
If the user enters a valid and existing username according to getpwnam(3), Prayer
does not search these first two CDB files, but skips directly to the second stage of
looking up user information.
lookup_username (path)
Path to a CDB file that maps usernames to records consisting of the user's
“registered name” and his/her affiliation (department), separated by a vertical bar
(‘|’). Additionally, if a second vertical bar follows, the account is regarded as
cancelled.
When presenting the search results, the usernames found are combined with the
default_domain to form email addresses. It is not possible at this time to let users
search for addresses in more than one domain using this facility.
lookup_fullname (path)
Path to a CDB file that maps usernames to “display names”, possibly provided by the
users themselves in some way. The display name of a user is used together with the
email address in recipient fields
Note that all four lookup options must be set to valid CDB files for the local
lookup to work, but more than one option may conceivably point to the same file.
ldap_server (string)
Name or address of LDAP server.
ldap_base_dn (string)
Base DN to search. After binding anonymously, Prayer performs a one-level-scope
search for entries with surname or mail attributes containing the search string. The
following attributes are fetched and presented:
• uid
• displayName
• cn (“registered name”)
• ou (“affiliation”)
• mail
• telephoneNumber
ldap_timeout (time)
Search timeout. Default: 30s.
HTTP and other frontend settings
use_http_port, use_https_port
Define a single HTTP[S] port to bind to. You can define an arbitary list of ports
of both kinds by using a series of separate use_http_port and use_https_port
directives, with one port on each line. Syntax:
use_http_port [interface:]port
use_https_port [interface:]port
interface can be an IP (v4 or v6) address or a hostname. If provided, it is passed
to getaddrinfo(3) for resolution, and the first resulting address is used to bind
to. Otherwise, prayer(8) binds to port on all interfaces.
ssl_default_port (number)
Prayer will put a warning on the login page for HTTP connections if both HTTP and
HTTPS sessions are available. This will provide a link to the SSL version of the
service, defaulting to port 443 or failing that the first defined HTTPS port.
ssl_default_port overrides the built in logic.
Should be rarely required now that Prayer automatically derives an appropriate port
if none is provided here.
ssl_cert_file (path)
Locatation of SSL certificate file (only used if SSL ports defined). Required if we
are going to provide SSL services.
ssl_privatekey_file (path)
Location of SSL private key file (only used if SSL ports defined). Required if we
are going to provide SSL services.
ssl_rsakey_lifespan (time)
Master server will regenerate shared RSA key at this interval. Default: 15m.
ssl_rsakey_freshen (time)
RSA key remains fresh in child process for this long after first actual use.
Default: 15m.
ssl_session_timeout (time)
SSL session cache TTL. Default: 0 (SSL session cache not used). prayer-ssl-prune(8)
should be run periodically to purge any stale session data from the DBD database.
egd_socket (path)
Path to entropy gathering daemon socket. If provided, it will be used in place of or
in addition to /dev/urandom
contact_email (string)
System administrator email address. This setting is currently not used. If you want
to display support information to your users, customise the templates.
fatal_dump_core (boolean)
Dump core on fatal() error. Default: false.
log_debug (boolean)
Enable somewhat more verbose logging, mainly in relation to SSL. Default: false.
fix_client_ipaddr (boolean)
Client must connect from consistent IP addresses. May be useful as a security
measure in LAN environments. Painful for dialup users whose connections may drop
out. Default: false.
gzip_allow_nets (string), gzip_deny_nets (string)
prayer-session(8) gzip-compresses pages sent to clients if:
1. gzip compression enabled at compile time,
2. use_gzip is set in user preferences,
3. User agent is known to support Content-Encoding: gzip,
4. User agent asks for Content-Encoding: gzip or x-gzip,
5. IP address of client appears in gzip_allow_nets or IP address of client does
not appear in gzip_deny_nets.
The format of these options is a sequence of ipaddr[/masklen] items, separated by
colons and whitespace (to allow for IPv6 addresses to be parsed easily). If masklen
is omitted, the item is interpreted as a full host address.
log_name_nets (string)
A network list in the same format as gzip_allow_nets above. To avoid delay when a
user logs in, prayer-session(8) only performs a reverse lookup of the remote address
if matches this list. Default: empty; no reverse lookup are performed.
limit_vm (number)
Virtual memory limit imposed on each process to stop runaway process killing system.
See setrlimit(2). Default: no limit.
http_max_method_size (number)
Prayer should in theory be able to cope with input of arbitrary size. In practice
however, the incoming request has to be stored somewhere and without limits an
attacker may exhaust available memory, causing a denial of service attack.
This sets the maximum size of the initial line of an HTTP request. Default: no
limit.
http_max_hdr_size (number)
Maximum for headers associated with this request.
http_max_body_size (number)
Maximum for HTTP payload. This is the most significant one in normal use.
draft_att_single_max (number)
Maximum size of a single attachment when composing a mail. Default: 0 (unlimited).
draft_att_total_max (number)
Maximum size of all attachments. Default: 0 (unlimited).
http_min_servers (number)
Minimum number of preforked prayer(8) HTTP servers. The master process forks new
slave processes whenever the number of idle slaves falls below this number, unless
the total number of slaves would exceed http_max_servers. Default: 4.
http_max_servers (number)
Maximum number of preforked prayer(8) HTTP servers (active and idle). The master
process does not, however, enforce any maximum number of idle slave processes; they
have to terminate voluntarily by timing out or serving the maximum number of
connections. Default: 64.
http_max_connections (number)
Maximum number of connections that each frontend server will process. Default: 0
(no limit).
http_timeout_idle (time)
Timeout for (dirty) spare server waiting for another HTTP connection. Default: 30s.
http_timeout_icons (time)
Timeout for HTTP connection that last served static content. Default: 10s.
http_timeout_session (time)
Timeout for HTTP connection that last served a session URL or has not served
anything yet. Default: 60s.
http_cookie_use_port (boolean)
Present HTTP cookies to browser as “username:port=value” rather than
“username=value”. Allows simultaneous login sessions from a single client browser.
However can leave a trail of cookies behind. Probably don't want this in the long
term, it's here for experimentation purposes only at the moment.
icon_expire_timeout (time)
The amount of time in the future to set the HTTP Expires: field for static content.
Default: 7d. (In contrast sessions URLs expire immediately: Browsers really
shouldn't be trying to cache this stuff, especially when it is coming in over
HTTPS).
Session specific configuration
session_idle_time (time)
Session switches to idle mode after this much time: connections to IMAP and accountd
servers are shut down. Default: 0 (idle mode disabled).
session_timeout (time)
Session terminates after this much idle time. ‘0’ means session never times out.
Default: 4h.
session_timeout_compose (time)
Session terminates after this much idle time instead when the last command was
‘compose’ or ‘sieve’. It should probably not be set lower than session_timeout.
Default: 0 (always use the same timeout).
stream_ping_interval (time)
Ping INBOX, Other, and Draft streams at this interval. Default: 5m.
stream_checkpoint (boolean)
Use CHECKPOINT instead of PING to “ping” streams. Default: true.
stream_misc_timeout (time)
Shut down Postponed, Preferences and Transfer streams entirely after this much idle
time, but only if idle mode doesn't beat us to it. Default: 0 (disabled).
log_ping_interval (time)
stat(2) log files at this interval to see if target file has been renamed or
removed. ‘0s’ means stat() log file every time something is logged. Default: 5m.
db_ping_interval (time)
Interval at which to re-read CDB files containing the local domain. Default: 30m.
recips_max_msg (number)
Maximum number of recipients per message. Default: 0 (unlimited).
recips_max_session (number)
Maximum number of recipients per session. Automatically creates file in
sending_block_dir if limit reached and that is defined. Default: 0 (unlimited).
sending_allow_dir (path)
Create empty file named user in this directory to disable recips_max_session for
that user.
sending_block_dir (path)
Create empty file named user in this directory to disable outgoing email for that
user (automatic defense against phishing attacks).
Display specific configuration
login_banner (string)
Used in the <title> and heading of the login page Default: "Webmail Service Login".
login_service_name (string)
Used in the <title> and elsewhere to refer to the webmail system after the user has
logged in. Default: "Prayer".
login_template (string)
Template to use on the login screen.
login_insert1_path (path)
Optional file to include in login page template (as $login_insert1).
login_insert2_path (path)
Optional file to include in login page template (as $login_insert2).
motd_path (path)
File to use as the part of the login page immediately following the login form.
ssl_encouraged (boolean)
If the user connects over unencrypted HTTP, do not show the login form on the start
(/) page. A link to /login, where the form is still displayed, is still provided.
Default: false. Ignored if ssl_redirect or ssl_required is true.
ssl_redirect (boolean)
If the user connects over unencrypted HTTP, return a ‘302’ redirect to the default
SSL port. Only the start (/) page is redirected and it may be possible to switch
between http and https after loggin in, subject to cookie rules.
Default: false.
ssl_required (boolean)
Return a ‘403 Forbidden’ error if the user tries to access anything over unencrypted
HTTP. ssl_redirect still has effect, however.
list_addr_maxlen (number)
The maximum number of characters to show from addresses on the mailbox list screen.
Default: 30.
list_subject_maxlen (number)
The maximum number of characters to show from the subject on the mailbox list
screen. Default: 30.
change_max_folders (number)
The maximum number of folders allowed in the quick folder change dropdown list. If
there would be too many folders, the quick list is disabled altogether. Only folders
that are expanded in the folder view are included.
Default: 20.
template_path (path)
Path to uncompiled template sets (directories). Default: "../templates" (relative
to tmp_dir).
template_set (string)
Template set to use. Default: "xhtml_strict".
template_use_compiled (boolean)
Use the compiled-in templates, ignoring template_path. Default: true.
theme Define themes and their colors. Semi-deprecated; Colours set with this directive
are only used by the xhtml_transitional template set. The xhtml_strict template set,
as well as the login screen, use CSS instead. It is still necessary to tell Prayer
which themes are available, however.
Syntax:
theme name description description
theme name element colour
theme name element colour
...
description is the label shown in the theme dropdown lists on the General
Preferences page.
element is one of fgcolor, fgcolor_link, bgcolor, bgcolor_banner, bgcolor_row1,
bgcolor_row2, bgcolor_status, bgcolor_status_none, fgcolor_quote1, fgcolor_quote2,
fgcolor_quote3, and fgcolor_quote4. The first three are not used by any standard
template set, but are available. Please study the templates to understand how the
rest are used.
colour is any valid HTML %Color value. Remember that strings containing hash marks
need to be quoted.
theme_default_main (string)
The name of the default theme.
theme_default_main (string)
The name of the default theme in help mode.
use_ispell_language
Ispell languages that we want to support, with some descriptive text for the
preferences screen. Syntax:
use_ispell_language wordlist description
Example:
use_ispell_language british "British English"
Paths etc.
aspell_path (path)
Location of Aspell Binary (takes precedence over ispell_path).
bin_dir (path)
Location of Prayer binaries (prayer(8) and prayer-session(8)). Default: none. Must
be set.
icon_dir (path)
Location of icon files. Default: none. Must be set.
ispell_path (path)
Location of Ispell Binary (backwards compatibility only).
log_dir (path)
Location of log files. Default: none. Must be set.
pid_dir (path)
Location for PID files of prayer and prayer-session master processes. Default:
none. Must be set.
sendmail_path (path)
Location of sendmail binary or drop in replacement such as Exim. Default:
/usr/lib/sendmail.
socket_dir (path)
Location for unix domain sockets which connect (prayer(8) to prayer-session(8)).
socket_split_dir (boolean)
Split socket directory into 64 subdirs keyed on first letter of sessionID. It is
possible to switch back and forth without moving sockets or killing sessions, since
prayer(8) tries both variants. In effect, this setting merely controls where
prayer-session(8) creates the socket files. Default: false.
init_socket_name (string)
Name of Unix domain socket (in socket_dir) used for initial handshake between prayer
and prayer-session processes when a user logs in. Default: none. Must be set.
ssl_session_dir (path)
Location of the SSL session cache database. Default: none. Must be set, even if the
SSL session cache is disabled.
static_dir (path)
Location of other static files (CSS). Default: none. If unset, Prayer will not
serve CSS files.
tmp_dir (path)
As the directory both daemons chdir(2) to at startup, it is where temporary files,
such as attachments and folders in transist during upload and download operations,
are written. Core files also end up here. Default: none. Must be set.
Defaults for user preferences
confirm_logout (boolean)
Confirmation dialogue when user logs out. Default: true.
confirm_expunge (boolean)
Confirmation dialogue when user hits expunge. Default: false.
confirm_rm (boolean)
Confirmation dialogue when user deletes mail folder or directory. Default: true.
default_domain (string)
Default domain for outgoing mail. Defaults to hostname setting.
expunge_on_exit (boolean)
Expunge deleted messages from inbox automatically on logout. Default: false.
html_inline (boolean)
Show text/html bodyparts inline. Content is scrubbed to remove dangerous tags.
text/html will be displayed in preference to text/plain if this is set Default:
true.
html_remote_images (boolean)
Show remote images automatically. If this is not set, "Show unsafe images" links
will appear on pages showing HTML mail. Default: false.
html_inline_auto (boolean)
Same as above for text/* bodyparts which start "<HTML>" (case-independent!) Does
anyone other than spammers actually use this? Default: true.
ispell_language (string)
Language for ispell. Default: "british".
msgs_per_page (number)
Number of messages per screen on message list screen. Default: 12.
msgs_per_page_max (number)
Maximum value that users are allowed to set msgs_per_page to. Default: 50.
msgs_per_page_min (number)
Minimum value that users are allowed to set msgs_per_page to. Default: 4.
abook_per_page (number)
Number of addressbook entries per page on address book list screen. Default: 12.
abook_per_page_max (number)
Maximum value that users are allowed to set abook_per_page to. Default: 50.
abook_per_page_min (number)
Minimum value that users are allowed to set abook_per_page to. Default: 4.
maildir (string)
Mail directory in user's account. Default: "". Typically needed with uw-imap.
Typically not needed with e.g. Dovecot or Courier.
suppress_dotfiles (boolean)
Supress dotfiles from directory listing. Default: true.
postponed_folder (string)
Name of the folder where messages to be sent later, a.k.a. drafts, are stored.
Default: "postponed-msgs".
sent_mail_folder (string)
Name of folder for sent mail. Default: "sent-mail".
small_cols (number)
Width of small compose textarea in columns. Default: 80.
small_rows (number)
Height of small compose textarea in lines. Default: 18.
large_cols (number)
Width of large compose textarea in columns. Default: 80.
large_rows (number)
Height of large compose textarea in lines. Default: 32.
sort_mode (string)
Default Sort mode for mailbox list. One of ARRIVAL, DATE, FROM, TO, CC, SIZE,
SUBJECT, REFERENCES, ORDEREDSUBJECT. Default: ARRIVAL is most efficient, and
recommended.
sort_reverse (boolean)
Favour reverse sort rather than normal sort order? Default: false.
abook_sort_mode (string)
Default Sort mode for addressbook list. One of: ORDERED, ALIAS, NAME, COMMENT,
ADDRESS. Default: ORDERED.
abook_sort_reverse (boolean)
Favour reverse sort rather than normal sort order? Default: false.
line_wrap_len (number)
Wrap lines at this many characters. Default: 76.
line_wrap_advanced (boolean)
Enable advanced line wrap options? Default: false.
line_wrap_on_reply (boolean)
Line wrap automatically on reply. Default: true.
line_wrap_on_spell (boolean)
Line wrap automatically on spell check. Default: true.
line_wrap_on_send (boolean)
Line wrap automatically on send. Default: true.
preserve_mimetype (boolean)
Send message Content-Type through to browser. If false, Content-Type is replaced
with ‘application/octet-stream’ which should force download to local disk, bypassing
any automatic processing of bodyparts by the User-Agent. Unclear at the moment
whether we need to do this, or whether this should be done selectively based on the
User-Agent. Default: true.
use_sent_mail (boolean)
Make the “Save copy” checkbox on the compose screen checked default. Default: true.
use_mark_persist (boolean)
Use persistent mark for aggregate operations. Default: false.
use_search_zoom (boolean)
Zoom automatically after sucessful search Default: true.
use_agg_unmark (boolean)
Unmark messages after sucessful aggregate operation. Default: true.
use_icons (boolean)
Use icons: may be overriden by value of User-Agent. Default: true.
use_welcome (boolean)
Enable welcome screen . Default: true.
use_tail_banner (boolean)
Duplicate banner icons (toolbar) at the bottom of the Message screen. Default:
true.
Hidden preferences
The following options are internally handled as user preferences, but the Preferences screen
no longer provides any means for changing them.
use_cookie (boolean)
Use HTTP cookie for Session-ID, if the browser supports cookies If disabled, or user
rejects the cookie, then the session-ID is stored in the URL. Default: true.
use_substitution (boolean)
Use page substiution rather than HTTP redirects. Faster, but the URLs that are
generated are less predictable. Page substitution and browser history mechanism
don't coexist well at the moment (Prayer would need to cache final page value for
each substiution event).
Default: true.
use_http_1_1 (boolean)
Allow HTTP/1.1, if the browser supports it. Default: true.
use_pipelining (boolean)
Allow HTTP/1.1 pipelining, if the browser supports it. Default: true.
use_persist (boolean)
Allow persistent HTTP/1.1 and HTTP/1.0 persistent connections, if the browser
supports them. Default: true.
use_short (boolean)
Allow short URLs, if the browser supports them. Default: true.
use_gzip (boolean)
Allow gzip compression, if the browser supports it. Default: true.
SEE ALSO
prayer(8), prayer-session(8)
AUTHORS
This manual page was put together by Magnus Holmgren <holmgren@debian.org> using
documentation written by
David Carter <dpc22@cam.ac.uk>.