Postfix address rewriting overview

The figure below zooms in on those parts of Postfix that are most involved with address rewriting activity. See the OVERVIEW document for an overview of the complete Postfix architecture. Names followed by a number are Postfix daemon programs, while unnumbered names represent Postfix queues or internal sources of mail messages.

		trivial- rewrite(8) (std form)						trivial- rewrite(8) (resolve)
		^ | | v						^ | | v
smtpd(8)	>-	cleanup(8)	->	incoming	->	active	->	qmgr(8)	-<	smtp(8)
qmqpd(8)										lmtp(8)
pickup(8)										local(8)
		^ |				^ | | v
		bounces forwarding notices				deferred

The table below summarizes all Postfix address manipulations. If you're reading this document for the first time, skip forward to " Address rewriting when mail is received". Once you've finished reading the remainder of this document, the table will help you to quickly find what you need.

Address manipulation	Scope	Daemon	Global turn-on control	Selective turn-off control
Rewrite addresses to standard form	all mail	trivial- rewrite(8)	append_at_myorigin, append_dot_mydomain, swap_bangpath, allow_percent_hack	local_header_rewrite_clients, remote_header_rewrite_domain
Canonical address mapping	all mail	cleanup(8)	canonical_maps	receive_override_options, local_header_rewrite_clients, remote_header_rewrite_domain
Address masquerading	all mail	cleanup(8)	masquerade_domains	receive_override_options, local_header_rewrite_clients, remote_header_rewrite_domain
Automatic BCC recipients	new mail	cleanup(8)	always_bcc, sender_bcc_maps, recipient_bcc_maps	receive_override_options
Virtual aliasing	all mail	cleanup(8)	virtual_alias_maps	receive_override_options
Resolve address to destination	all mail	trivial- rewrite(8)	none	none
Mail transport switch	all mail	trivial- rewrite(8)	transport_maps	none
Relocated users table	all mail	trivial- rewrite(8)	relocated_maps	none
Generic mapping table	outgoing SMTP mail	smtp(8)	smtp_generic_maps	none
Local alias database	local mail only	local(8)	alias_maps	none
Local per-user .forward files	local mail only	local(8)	forward_path	none
Local catch-all address	local mail only	local(8)	luser_relay	none