NetBSD/gnu/dist/postfix/README_FILES/ADDRESS_CLASS_README
2003-03-08 19:05:29 +00:00

101 lines
4.2 KiB
Plaintext

Introduction
============
Postfix version 2.0 introduces the concept of address classes.
This is a way of grouping recipient addresses by their delivery
method. The idea comes from discussions with Victor Duchovni.
Benefits of address classes are:
- You no longer need to specify all the virtual(8) mailbox domains
in the Postfix transport map. The virtual(8) delivery agent has
become a first-class citizen just like local(8) or smtp(8).
- On mail gateway systems, separation of inbound mail relay traffic
from outbound traffic. This eliminates a problem where inbound
mail deliveries could become resource starved in the presence of
a high volume of outbound mail.
- The SMTP server rejects unknown recipients in a more consistent
manner than was possible with previous Postfix versions.
The list with "bad news" is at the end of this file :-)
What address classes does Postfix implement?
============================================
Initially the list of address classes is hard coded, but this is
meant to become extensible:
-------------------------------------------------------------------
Class Description
-------------------------------------------------------------------
local For UNIX accounts and for traditional /etc/aliases
Domain names are listed in $mydestination (or match the IP
address listed with $inet_interfaces)
Known recipients are listed in $local_recipient_maps (this
information is currently used by the Postfix SMTP server
only; if $local_recipient_maps is empty, the Postfix
SMTP server accepts all recipients)
Default delivery agent: local
virtual For hosted domains that are aliased to mailboxes in other
alias domains
Known recipients are listed in $virtual_alias_maps (default
is $virtual_maps for Postfix 1.1 compatibility)
Domain names are listed in $virtual_alias_domains (default
is $virtual_alias_maps for Postfix 1.1 compatibility)
virtual For hosted domains with their own mailboxes
mailbox Known recipients are listed in $virtual_mailbox_maps (if
this parameter is empty, the Postfix SMTP server accepts
all recipients for domains listed in $virtual_mailbox_domains)
Domain names are listed in $virtual_mailbox_domains (default
is $virtual_mailbox_maps for Postfix 1.1 compatibility)
Default delivery agent: virtual
relay For remote destinations that list your system as MX host
Domain names are listed in $relay_domains
Known recipients are listed in $relay_recipient_maps (if
this parameter is empty, the Postfix SMTP server accepts
all recipients for domains listed in $relay_domains)
Default delivery agent: relay (clone of default smtp agent)
other Restricted to mail from authorized clients
Default delivery agent: smtp
No domain table
No recipient table
-------------------------------------------------------------------
Incompatibilities with Postfix 1.1
==================================
- virtual_maps is replaced by virtual_alias_maps (for address
lookups) and virtual_alias_domains (for the names of what were
formerly called "Postfix-style virtual domains").
For backwards compatibility with Postfix version 1.1, the new
virtual_alias_maps parameter defaults to $virtual_maps, and the
new virtual_alias_domains parameter defaults to $virtual_alias_maps.
- virtual_mailbox_maps now has a companion parameter called
virtual_mailbox_domains (for the names of domains served by the
virtual delivery agent). virtual_mailbox_maps is now used for
address lookups only.
For backwards compatibility with Postfix version 1.1,, the new
virtual_mailbox_domains parameter defaults to $virtual_mailbox_maps.
- Introduction of relay_recipient_maps, so that the Postfix SMTP
server can block mail for relay recipients that don't exist. This
list is empty by default.
- The local_recipient_maps feature is now turned on by default, so
that the Postfix SMTP server rejects mail for unknown local
recipients. This is enabled by default. See the LOCAL_RECIPIENT_README
file hints and tips.
- Introduction of relay delivery transport in master.cf. This helps
to avoid mail delivery scheduling problems on inbound mail relays,
but may require that you update your "defer_transports" setting.