Config Variables¶

You can use special variables in several places:

mail_location setting and namespace locations
static User Databases (userdb) and passwd-file userdb template strings
LDAP and SQL User Databases (userdb) query strings
log prefix for imap/pop3 process
Plugin settings

Global variables¶

Global variables that work everywhere are:

Long name	Description
%%	‘%’ character. See Mailbox sharing between users for further information about %% variables
env:<name>	Environment variable <name>
system:<name>	Get a system variable, see below for list of supported names.
process:<name>	Get a process variable, see below for list of supported names.

If var_expand_crypt Plugin is loaded, these also work globally:

Long name	Description
encrypt; <parameters>:<field>	Encrypt field New in version 2.2.29.
decrypt; <parameters>:<field>	Decrypt field New in version 2.2.29.

Supported system variables¶

cpu_count: Number of CPUs available. Works only on Linux and FreeBSD-like systems. Can be overridden with NCPU environment variable. This needs to be included in import_environment.
hostname: Hostname (without domain). Can be overridden with DOVECOT_HOSTNAME environment variable. This needs to be included in import_environment.

Supported process variables¶

pid: Current process ID.
uid: Effective user ID of the current process.
gid: Effective group ID of the current process.

User variables¶

Variables that work nearly everywhere where there is a username:

Variable	Long name	Description
See also Global variables
%u	user	full username (e.g. user@domain)
%n	username	user part in user@domain, same as %u if there’s no domain
%d	domain	domain part in user@domain, empty if user with no domain
%s	service	imap, pop3, smtp, lda (and doveadm, etc.)
	session	session ID for this client connection (unique for 9 years)
	auth_user	SASL authentication ID (e.g. if master user login is done, this contains the master username). If username changes during authentication, this value contains the original username. Otherwise the same as %{user}. New in version 2.2.11.
	auth_username	user part in %{auth_user} New in version 2.2.11.
	auth_domain	domain part in %{auth_user} New in version 2.2.11.

Mail service user variables¶

Variable	Long name	Description
See also Global variables and User variables
%l	local_ip	local IP address Changed in version 2.3.14: variable long name changed
%r	remote_ip	remote IP address Changed in version 2.3.14: variable long name changed
	userdb:<name>	Return userdb extra field “name”. %{userdb:name:default} returns “default” if “name” doesn’t exist (not returned if name exists but is empty) New in version 2.2.19.
	lip	Deprecated version of %{local_ip} Deprecated since version 2.3.14.
	rip	Deprecated version of %{remote_ip} Deprecated since version 2.3.14.

Mail user variables¶

Variable	Long name	Description
See also Global variables, User variables and Mail service user variables
%h	home	home directory. Use of ~/ is better whenever possible.
	hostname	Expands to the hostname setting. Overrides the global %{hostname}.

Login variables¶

Variable	Long name	Description
See also Global variables and User variables
	local_name	TLS SNI hostname, if given New in version 2.2.26.
%l	local_ip	local IP address New in version 2.3.14: For older versions use %{lip}
%r	remote_ip	remote IP address New in version 2.3.14: For older versions use %{rip}
%a	local_port	local port New in version 2.3.14: For older versions use %{lport}
%b	remote_port	remote port New in version 2.3.14: For older versions use %{rport}
	real_remote_ip	Same as %{remote_ip}, except in proxy setups contains the remote proxy’s IP instead of the client’s IP New in version 2.3.14: For older versions use %{real_rip}
	real_local_ip	Same as %{local_ip}, except in proxy setups contains the local proxy’s IP instead of the remote proxy’s IP New in version 2.3.14: For older versions use %{real_lip}
	real_remote_port	Similar to %{real_rip} except for port instead of IP New in version 2.3.14: For older versions use %{real_rport}
	real_local_port	Similar to %{real_lip} except for port instead of IP New in version 2.3.14: For older versions use %{real_lport}
	rip	Deprecated version of %{remote_ip} Deprecated since version 2.3.14.
	lip	Deprecated version of %{local_ip} Deprecated since version 2.3.14.
	rport	Deprecated version of %{remote_port} Deprecated since version 2.3.14.
	lport	Deprecated version of %{local_port} Deprecated since version 2.3.14.
	real_rip	Deprecated version of %{real_remote_ip} Deprecated since version 2.3.14.
	real_lip	Deprecated version of %{real_local_ip} New in version 2.2.0. Deprecated since version 2.3.14.
	real_rport	Deprecated version of %{real_remote_port} New in version 2.2.0. Deprecated since version 2.3.14.
	real_lport	Deprecated version of %{real_local_port} New in version 2.2.0. Deprecated since version 2.3.14.
%m	mechanism	Authentication (SASL) Mechanisms e.g. PLAIN New in version 2.3.14.
	mech	Deprecated version of %{mechanism} Deprecated since version 2.3.14.
%c	secured	“TLS” with established SSL/TLS connections, “TLS handshaking”, or “TLS [handshaking]: error text” if disconnecting due to TLS error. “secured” with secured connections. Otherwise empty.
%k	ssl_security	TLS session security string. New in version 2.4.0 (CE): If HAProxy is configured and it terminated the TLS connection, contains “(proxied)”. New in version 3.0.0 (Pro): If HAProxy is configured and it terminated the TLS connection, contains “(proxied)”.
	ssl_ja3	JA3 string composed from TLS Client Hello. New in version 2.4.0 (CE). New in version 3.0.0 (Pro).
	ssl_ja3_hash	MD5 hash from JA3 string composed from TLS Client Hello. New in version 2.4.0 (CE). New in version 3.0.0 (Pro).
%e	mail_pid	PID for process that handles the mail session post-login
	original_user	Same as %{user}, except using the original username the client sent before any changes by auth process. With master user logins (also with `auth_master_user_separator` based logins), this contains only the original master username. New in version 2.3.14.
	original_username	Same as %{username}, except using the original username New in version 2.3.14.
	original_domain	Same as %{domain}, except using the original username New in version 2.3.14.
	orig_user	Deprecated version of %{original_user} New in version 2.2.6. Deprecated since version 2.3.14.
	orig_username	Deprecated version of %{original_username} New in version 2.2.6. Deprecated since version 2.3.14.
	orig_username	Deprecated version of %{original_domain} New in version 2.2.6. Deprecated since version 2.3.14.
	listener	Socket listener name as specified in config file, which accepted the client connection. New in version 2.2.19.
	passdb:<name>	Return passdb extra field “name”. %{passdb:name:default} returns “default” if “name” doesn’t exist (not returned if name exists but is empty). Note that this doesn’t work in passdb/userdb ldap’s pass_attrs or user_attrs. New in version 2.2.19.
	passdb:forward_<name>	Used by proxies to pass on extra fields to the next hop, see Forwarding fields New in version 2.2.29.

Authentication variables¶

Variable	Long name	Description
See also Global variables and User variables
	domain_first	For “username@domain_first@domain_last” style usernames New in version 2.2.6.
	domain_last	For “username@domain_first@domain_last” style usernames New in version 2.2.6.
	local_name	TLS SNI hostname, if given New in version 2.2.26.
%l	local_ip	local IP address New in version 2.3.13: For older versions use %{lip}
%r	remote_ip	remote IP address New in version 2.3.13: For older versions use %{rip}
%a	local_port	local port New in version 2.3.13: For older versions use %{lport}
%b	remote_port	remote port New in version 2.3.13: For older versions use %{rport}
	real_remote_ip	Same as %{remote_ip}, except in proxy setups contains the remote proxy’s IP instead of the client’s IP New in version 2.3.13: For older versions use %{real_rip}
	real_local_ip	Same as %{local_ip}, except in proxy setups contains the local proxy’s IP instead of the remote proxy’s IP New in version 2.3.13: For older versions use %{real_lip}
	real_remote_port	Similar to %{real_rip} except for port instead of IP New in version 2.3.13: For older versions use %{real_rport}
	real_local_port	Similar to %{real_lip} except for port instead of IP New in version 2.3.13: For older versions use %{real_lport}
	rip	Deprecated version of %{remote_ip} Deprecated since version 2.3.13.
	lip	Deprecated version of %{local_ip} Deprecated since version 2.3.13.
	rport	Deprecated version of %{remote_port} Deprecated since version 2.3.13.
	lport	Deprecated version of %{local_port} Deprecated since version 2.3.13.
	real_rip	Deprecated version of %{real_remote_ip} Deprecated since version 2.3.13.
	real_lip	Deprecated version of %{real_local_ip} New in version 2.2.0. Deprecated since version 2.3.13.
	real_rport	Deprecated version of %{real_remote_port} New in version 2.2.0. Deprecated since version 2.3.13.
	real_lport	Deprecated version of %{real_local_port} New in version 2.2.0. Deprecated since version 2.3.13.
%p	client_pid	process ID of the authentication client
	session_pid	For user logins: The PID of the IMAP/POP3 process handling the session. New in version 2.2.7.
%m	mechanism	Authentication (SASL) Mechanisms e.g. PLAIN New in version 2.3.13.
	mech	Deprecated version of %{mechanism} Deprecated since version 2.3.13.
%w	password	cleartext password from cleartext authentication mechanism
%c	secured	“TLS” with established SSL/TLS connections, “secured” with secured connections. Otherwise empty.
	ssl_ja3_hash	MD5 hash from JA3 string composed from TLS Client Hello. New in version 2.4.0 (CE). New in version 3.0.0 (Pro).
%k	cert	“valid” if client had sent a valid client certificate, otherwise empty.
	login_user	For master user logins: Logged in user@domain
	login_username	For master user logins: Logged in user
	login_domain	For master user logins: Logged in domain
	master_user	For master user logins: The master username New in version 2.2.7.
	original_user	Same as %{user}, except using the original username the client sent before any changes by auth process New in version 2.3.13.
	original_username	Same as %{username}, except using the original username New in version 2.3.13.
	original_domain	Same as %{domain}, except using the original username New in version 2.3.13.
	orig_user	Deprecated version of %{original_user} New in version 2.2.6. New in version 2.2.13: Works in auth process. Deprecated since version 2.3.13.
	orig_username	Deprecated version of %{original_username} New in version 2.2.6. New in version 2.2.13: Works in auth process. Deprecated since version 2.3.13.
	orig_username	Deprecated version of %{original_domain} New in version 2.2.6. New in version 2.2.13: Works in auth process. Deprecated since version 2.3.13.
	passdb:<name>	Return passdb extra field “name”. %{passdb:name:default} returns “default” if “name” doesn’t exist (not returned if name exists but is empty). Note that this doesn’t work in passdb/userdb ldap’s pass_attrs or user_attrs. New in version 2.2.19.
	userdb:<name>	Return userdb extra field “name”. Note that this can also be used in passdbs to access any userdb_* extra fields added by previous passdb lookups. %{userdb:name:default} returns “default” if “name” doesn’t exist (not returned if name exists but is empty). Note that this doesn’t work in passdb/userdb ldap’s pass_attrs or user_attrs. New in version 2.2.19.
	client_id	If `imap_id_retain` is enabled this variable is populated with the client ID request as IMAP arglist. For directly logging the ID see the `imap_id_received` event. New in version 2.2.29.
	passdb:forward_<name>	Used by proxies to pass on extra fields to the next hop, see Forwarding fields New in version 2.2.29.
%!		Internal ID number of the current passdb/userdb.

Modifiers¶

You can apply a modifiers for each variable (e.g. %Us or %U{service} = POP3):

%L - lowercase
%U - uppercase
%E - escape ‘”’, “’” and ‘' characters by inserting ‘' before them. Note that variables in SQL queries are automatically escaped, you don’t need to use this modifier for them.
%X - parse the variable as a base-10 number, and convert it to base-16 (hexadecimal)
%R - reverse the string
%N - take a 32bit hash of the variable and return it as hex. You can also limit the hash value. For example %256Nu gives values 0..ff. You might want padding also, so %2.256Nu gives 00..ff. This can be useful for example in dividing users automatically to multiple partitions.

This is “New Hash”, based on MD5 to give better distribution of values (no need for any string reversing kludges either).

New in version 2.2.3.

%H - Same as %N, but use “old hash” (not recommended anymore)

%H hash function is a bit bad if all the strings end with the same text, so if you’re hashing usernames being in user@domain form, you probably want to reverse the username to get better hash value variety, e.g. %3RHu.

%{<hash algorithm>;rounds=<n>,truncate=<bits>,salt=s,format=<hex|hexuc|base64|base64url>:field}

Generic hash function that outputs a hex (by default) or base64 value. Hash algorithm is any of the supported ones, e.g. md5, sha1, sha256. Also “pkcs5” is supported using SHA256.

Example:
%{sha256:user} or %{md5;truncate=32:user}.
New in version 2.2.27.

%M - return the string’s MD5 sum as hex.
%D - return “sub.domain.org” as “sub,dc=domain,dc=org” (for LDAP queries)
%T - Trim trailing whitespace

You can take a substring of the variable by giving optional offset followed by ‘.’ and width after the ‘%’ character. For example %2u gives first two characters of the username. %2.1u gives third character of the username.

If the offset is negative, it counts from the end, for example %-2.2i gives the UID mod 100 (last two characters of the UID printed in a string). If a positive offset points outside the value, empty string is returned, if a negative offset does then the string is taken from the start.

If the width is prefixed with zero, the string isn’t truncated, but only padded with ‘0’ character if the string is shorter.

Note

%04i may return “0001”, “1000” and “12345”. %1.04i for the same string would return “001”, “000” and “2345”.

If the width is negative, it counts from the end.

Note

%0.-2u gives all but the last two characters from the username.

New in version 2.2.13.

The modifiers are applied from left-to-right order, except the substring is always taken from the final string.

Conditionals¶

New in version 2.2.33.

It’s possible to use conditionals in variable expansion. The generic syntax is

%{if;value1;operator;value2;value-if-true;value-if-false}

Each of the value fields can contain another variable expansion, facilitating for nested ifs. Both %f and %{field} syntaxes work.

Escaping is supported, so it’s possible to use values like %, : or ; that expand to the literal %, : or ; characters. Values can have spaces and quotes without any special escaping.

Note that currently unescaped : cuts off the if statement and ignores everything after it.

Following operators are supported

Operator	Explanation
==	NUMERIC equality
!=	NUMERIC inequality
<	NUMERIC less than
<=	NUMERIC less or equal
>	NUMERIC greater than
>=	NUMERIC greater or equal
eq	String equality
ne	String inequality
lt	String inequality
le	String inequality
gt	String inequality
ge	String inequality
*	Wildcard match (mask on value2)
!*	Wildcard non-match (mask on value2)
~	Regular expression match (pattern on value2, extended POSIX)
!~	String inequality (pattern on value2, extended POSIX)

Examples:

# If %u is "testuser", return "INVALID". Otherwise return %u uppercased.
%{if;%u;eq;testuser;INVALID;%Uu}

# Same as above, but for use nested IF just for showing how they work:
%{if;%{if;%u;eq;testuser;a;b};eq;a;INVALID;%Uu}