### 6.2.1 Exim configuration

The Exim configuration is built so that a list created within Mailman automatically appears to Exim without the need for defining any additional aliases.

The drawback of this configuration is that it will work poorly on systems supporting lists in several different mail domains. While Mailman handles virtual domains, it does not yet support having two distinct lists with the same name in different virtual domains, using the same Mailman installation. This will eventually change. (But see below for a variation on this scheme that should accommodate virtual domains better.)

The configuration file excerpts below are for use in an already functional Exim configuration, which accepts mail for the domain in which the list resides. If this domain is separate from the others handled by your Exim configuration, then you'll need to:

- add the list domain, ``my.list.domain'' to local_domains

- add a ``domains=my.list.domain'' option to the director (router) for the list

- (optional) exclude that domain from your other directors (routers)

Note: The instructions in this document should work with either Exim 3 or Exim 4. In Exim 3, you must have a local_domains configuration setting; in Exim 4, you most likely have a local_domains domainlist. If you don't, you probably know what you're doing and can adjust accordingly. Similarly, in Exim 4 the concept of ``directors'' has disappeared - there are only routers now. So if you're using Exim 4, whenever this document says ``director'', read ``router''.

Whether you are using Exim 3 or Exim 4, you will need to add some macros to the main section of your Exim config file. You will also need to define one new transport. With Exim 3, you'll need to add a new director; with Exim 4, a new router plays the same role.

Finally, the configuration supplied here should allow co-habiting Mailman 2.0 and 2.1 installations, with the proviso that you'll probably want to use `mm21` in place of `mailman` - e.g., MM21_HOME, mm21_transport, etc.