exim4 configuration instruction

[grizzlyfute]

Creating missing exim4 documentation. File contains instruction to set up the exim4 mail server to work with sympa command aliases and with the auto-generated list aliases. This was tested on Debian 11 with single domain configuration.

[ikedas]

@grizzlyfute , Thank you for adding instruction! Please discuss about this PR at issue #57.

[racke]

Exim can read the aliases from a text file, so newaliases isn't necessary. /etc/aliases is not a good place to put the generic aliases, it is better to add routers/transports for them.

# Sympa generic aliases for "sympa" and "listmaster"
sympa_queue_aliases:
  debug_print = "R: sympa queue aliases for $local_part@$domain"
  driver = accept
  domains = list.sympa.pm
  local_parts = sympa : listmaster
  transport = sympa_queue_transport
  no_more

# Sympa generic aliases for "bounce" and "abuse-feedback-report"
sympa_bouncequeue_aliases:
  debug_print = "R: sympa bouncequeue aliases for $local_part@$domain"
  driver = accept
  domains = list.sympa.pm
  local_parts = bounce : abuse-feedback-report
  transport = sympa_bounce_queue_transport
  no_more
Transports
# Sympa transport for queue program
sympa_queue_transport:
  driver = pipe
  command = /usr/local/sympa/bin/queue ${local_part}\@$domain
  user = sympa
  group = sympa

# Sympa transport for bouncequeue program
sympa_bounce_queue_transport:
  driver = pipe
  command = /usr/local/sympa/bin/bouncequeue ${local_part}\@$domain
  user = sympa
  group = sympa

[grizzlyfute]

Hello,

Thanks for the update and the sample. You have right, /etc/aliases and new aliases are not necessary. I do not know well the exim mechanism yet. I will report it on my testing environment.

[grizzlyfute]

New version taking your advices into consideration. Thank you.

[grizzlyfute]

Hello, Thank for your patience. Aliases program is now set to none. Therefore the link section is no more needed. I have removed it.

[ikedas]

@grizzlyfute and @racke , sorry for not responding for so long. If there are no problems, I think I will merge this PR. Is it OK?

And @grizzlyfute, please let us know your full name. The authors' names must be listed in the AUTHORS.md file to satisfy the license.

[grizzlyfute]

Hello. Its is ok for me. I will send you my full name.

[grizzlyfute]

My full name is MALMARTEL Rémy. You can include it to the Authors.md, but doesn't matter if it not appears.