1
The stable Postfix release is called postfix-2.7.x where 2=major
2
release number, 7=minor release number, x=patchlevel. The stable
3
release never changes except for patches that address bugs or
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emergencies. Patches change the patchlevel and the release date.
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New features are developed in snapshot releases. These are called
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postfix-2.8-yyyymmdd where yyyymmdd is the release date (yyyy=year,
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mm=month, dd=day). Patches are never issued for snapshot releases;
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instead, a new snapshot is released.
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The mail_release_date configuration parameter (format: yyyymmdd)
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specifies the release date of a stable release or snapshot release.
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If you upgrade from Postfix 2.5 or earlier, read RELEASE_NOTES-2.6
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Major changes - performance
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---------------------------
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[Feature 20100101] Periodic cache cleanup for the verify(8) cache
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database. The time between cache cleanup runs is controlled with
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the address_verify_cache_cleanup_interval (default: 12h) parameter.
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Cache cleanup increases the database access latency, so this should
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not be run more often than necessary.
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[Feature 20091109] Improved before-queue filter performance. With
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"smtpd_proxy_options = speed_adjust", the Postfix SMTP server
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receives the entire message before it connects to a before-queue
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content filter. This means you can run more SMTP server processes
30
with the same number of running content filter processes, and thus,
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handle more mail. This feature is off by default until it is proven
32
to create no new problems.
34
This addresses a concern of people in Europe who want to reject all
35
bad mail with a before-queue filter. The alternative, an after-queue
36
filter, means they would have to discard bad mail (which is illegal)
37
or bounce bad mail (which violates good network citizenship).
39
NOTE 1: When this feature is turned on, a filter cannot selectively
40
reject recipients of a multi-recipient message. It is OK to reject
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all recipients of the same multi-recipient message, as is deferring
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or accepting all recipients of the same multi-recipient message.
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NOTE 2: This feature increases the minimum amount of free queue
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space by $message_size_limit. The extra space is needed to save the
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message to a temporary file.
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To keep the performance overhead low, the same temporary file is
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reused with successive mail transactions (the file is of course
50
truncated before reuse, so there is no information leakage).
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Major changes - sender reputation
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---------------------------------
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[Feature 20100117] The FILTER action in access maps or header/body_checks
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now supports sender reputation schemes that dynamically choose the
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SMTP source IP address. Typically, mail is split into classes, and
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all mail in class X is sent out from an SMTP client IP address that
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is reserved for class X.
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This is implemented by specifying FILTER actions with empty next-hop
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destinations in access maps or header/body_checks, and by configuring
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in master.cf one Postfix SMTP client for each SMTP source IP address,
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where each client has its own "-o myhostname" and "-o smtp_bind_address"
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[Feature 20091209] sender_dependent_default_transport_maps, a
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per-sender override for default_transport. The original motivation
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is to use different output channels (with different source IP
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addresses) for different sender addresses, in order to keep their
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IP-based reputations separate from each other.
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The result value syntax is that of default_transport, not transport_maps.
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Thus, sender_dependent_default_transport_maps does not support the
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special transport_maps result value syntax for null transport, null
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nexthop, or null email address.
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This feature makes sender_dependent_relayhost_maps pretty much
79
redundant (though sender_dependent_relayhost_maps will often be
80
easier to use because that is the only thing people want to override).
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Major changes - address verification
83
------------------------------------
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[Incompat 20100101] The verify(8) service now uses a persistent
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cache by default (address_verify_map = btree:$data_directory/verify_cache).
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To disable, specify "address_verify_map =" in main.cf.
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When periodic cache cleanup is enabled (the default), the verify(8)
90
server now requires that the cache database supports the "delete"
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and "sequence" operations. To disable periodic cache cleanup specify
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a zero address_verify_cache_cleanup_interval value.
94
[Feature 20100101] Periodic cache cleanup for the verify(8) cache
95
database. The time between cache cleanup runs is controlled with
96
the address_verify_cache_cleanup_interval (default: 12h) parameter.
97
Cache cleanup increases the database access latency, so this should
98
not be run more often than necessary.
100
Major changes - content filter
101
------------------------------
103
[Incompat 20100117] The meaning of an empty filter next-hop destination
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has changed (for example, "content_filter = foo:" or "FILTER foo:").
105
Postfix now uses the recipient domain, instead of using $myhostname
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as in Postfix 2.6 and earlier. To restore the old behavior specify
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"default_filter_nexthop = $myhostname", or specify a non-empty
108
next-hop content filter destination.
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This compatibility option is not needed with SMTP-based content
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filters, because these always have an explicit next-hop destination.
113
With pipe-based filters that specify no next-hop destination, the
114
compatibility option restores the FIFO order of deliveries. Without
115
the compatibility option, the delivery order for filters without
116
next-hop destination changes to round-robin domain selection.
118
[Feature 20100117] The FILTER action in access maps or header/body_checks
119
now supports sender reputation schemes that dynamically choose the
120
SMTP source IP address. Typically, mail is split into classes, and
121
all mail in class X is sent out from an SMTP client IP address that
122
is reserved for class X.
124
This is implemented by specifying FILTER actions with empty next-hop
125
destinations in access maps or header/body_checks, and by configuring
126
in master.cf one Postfix SMTP client for each SMTP source IP address,
127
where each client has its own "-o myhostname" and "-o smtp_bind_address"
130
[Feature 20091109] Improved before-queue filter performance. With
131
"smtpd_proxy_options = speed_adjust", the Postfix SMTP server
132
receives the entire message before it connects to a before-queue
133
content filter. This means you can run more SMTP server processes
134
with the same number of running content filter processes, and thus,
135
handle more mail. This feature is off by default until it is proven
136
to create no new problems.
138
This addresses a concern of people in Europe who want to reject all
139
bad mail with a before-queue filter. The alternative, an after-queue
140
filter, means they would have to discard bad mail (which is illegal)
141
or bounce bad mail (which violates good network citizenship).
143
NOTE 1: When this feature is turned on, a filter cannot selectively
144
reject recipients of a multi-recipient message. It is OK to reject
145
all recipients of the same multi-recipient message, as is deferring
146
or accepting all recipients of the same multi-recipient message.
148
NOTE 2: This feature increases the minimum amount of free queue
149
space by $message_size_limit. The extra space is needed to save the
150
message to a temporary file.
152
To keep the performance overhead low, the same temporary file is
153
reused with successive mail transactions (the file is of course
154
truncated before reuse, so there is no information leakage).
156
Major changes - milter
157
----------------------
159
[Feature 20090606] Support for header checks on Milter-generated
160
message headers. This can be used, for example, to control mail
161
flow with Milter-generated headers that carry indicators for badness
162
or goodness. For details, see the postconf(5) section for
163
"milter_header_checks". Currently, all header_checks features are
164
implemented except PREPEND.
166
Major changes - multi-instance support
167
--------------------------------------
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[Incompat 20090606] The "postmulti -e destroy" command no longer
170
attempts to remove files that are created AFTER "postmulti -e
171
create". It still works as expected immediately after creating an
172
instance by mistake. Trying to automatically remove other files
173
is too risky because Postfix-owned directories are by design not
added
removed
RELEASE_NOTES-2.7
