Exim
Exim is a message transfer agent (MTA) under the GNU license.
Configuration
The configuration file should contain:
- Macros
- Main configuration option settings
Lines can be commented out using #.
Main configuration settings are values that are defined in the file as foo = bar.
There are named lists which are defined by the type of list followed by the name of the list and they come in the form of list-type list-name = list-values.
There are 4 types of named lists:
- domainlist
- hostlist
- addresslist
- localpartlist
Items in lists are separated with a colon : but can be changed by first defining a list with <FS, where FS is the field separator character. Items can be negated with an exclamation !. List values may refer to other named lists with a plus +.
Patterns that start with the name of a single-key lookup type followed by a semicolon must be followed by a filename suitable for the lookup type. For example, lsearch;/etc/trustedmailhosts will search for a key in the file /etc/trustedmailhosts which should contain data formatted as key: value.
Lists are checked from left to right. The first match or negation that is found is the result.
Common Settings
- primary_hostname
- The FQDN, otherwise if unset, Exim uses the uname system function to obtain the hostname
- domainlist local_domains = @
- identify domains that are to be delivered on the local host. The
@is a special form of entry which means "the name of the local host"
- domainlist relay_to_domains =
- Lists domains that allows this server to relay to. Default is empty and no relaying is permitted
- hostlist relay_from_hosts
- List of domains or IPs to permit relaying from. Default is the IP address of the loopback device.