-$Cambridge: exim/doc/doc-txt/README.SIEVE,v 1.7 2005/08/30 10:55:52 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/README.SIEVE,v 1.10 2006/04/25 10:44:57 ph10 Exp $
Notes on the Sieve implementation for Exim
Exim Implementation
-The Exim Sieve implementation offers the core as defined by draft
-3028bis-4 (next version of RFC 3028 that fixes specification mistakes),
-the "envelope" (3028bis), the "fileinto" (3028bis), the "copy" (RFC 3894)
-and the "vacation" (draft-ietf-sieve-vacation-02.txt) extension, the
-"i;ascii-numeric" comparator (RFC 2244).
+The Exim Sieve implementation offers the core as defined by
+draft-ietf-sieve-3028bis-05.txt (next version of RFC 3028 that fixes
+specification mistakes), the "envelope" test (3028bis), the "fileinto"
+action (3028bis), the "copy" action (RFC 3894), the "vacation" action
+(draft-ietf-sieve-vacation-05.txt) and the "i;ascii-numeric" comparator
+extension (RFC 2244).
The Sieve filter is integrated in Exim and works very similar to the
Exim filter: Sieve scripts are recognized by the first line containing
This may be implemented in future by adding a header line to mails that
are filed into "inbox" due to an error in the filter.
+The automatic replies generated by "vacation" do not contain an updated
+"references" header field.
+
Semantics Of Keep
been reset.
-Semantics of Fileinto
+Semantics Of Fileinto
RFC 3028 does not specify if "fileinto" tries to create a mail folder,
in case it does not exist. This implementation allows to configure
the Exim specification for details.
-Sieve Syntax and Semantics
+Allof And Anyof Test
+
+RFC 3028 does not specify if these tests use shortcut/lazy evaluation.
+Exim uses shortcut evaluation.
+
+
+Action Reordering
+
+RFC 3028 does not specify if actions may be executed out of order.
+Exim may execute them out of order, e.g. messages may be filed to
+folders or forwarded in a different order than specified, because
+those actions only setup delivery, but do not execute it themselves.
+
+
+Wildcard Matching
+
+RFC 3028 is not exactly clear if comparators act on unicode characters
+or on octets containing their UTF-8 representation. As it turns out,
+many implementations go the second way. This does not make a difference
+but for wildcard matching and octet-wise comparison. Working on unicode
+means a dot matches a character. Working on UTF-8 means the dot matches
+a single octet of a multi-octet sequence. For octet-wise comparisons,
+working on UTF-8 means arbitrary byte sequences in headers can not be
+matches, as they are rarely correct UTF-8 sequences and can thus not be
+expressed as string literal. This implementation works on unicode, but
+this may be changed in case RFC3028bis specifies this issue safe and sound.
+
+
+Sieve Syntax And Semantics
RFC 3028 confuses syntax and semantics sometimes. It uses a generic
grammar as syntax for commands and tests and performs many checks during