When attaching a file to a message (composing a new message), the +MIME type of the attached file is choosen based on the file extension +from the mapping list defined in the mime.types file(s). +Sylpheed defines its MIME type mapping table by loading the +system wide MIME types file, then the user file. +The systeme file is SYSCONFDIR/mime.types (SYSCONFDIR can +be defined a compile time), or if it does not exist, /etc/mime.types. +The user file is $HOME/.sylpheed/mime.types. +
A mime.types file consist of one MIME type definition per line,
+each definition line starting with the name of the MIME type, followed by
+a space separated list of the corresponding file extensions.
+The file can contain empty lines, and comments start with the #
+character and close at line's end.
+
Following is a typical mime.types file (an extract of mine): +
+
+# This file controls what Internet media types are sent to the client for +# given file extension(s). Sending the correct media type to the client +# is important so they know how to handle the content of the file. +# The Internet media type registry is at +# <ftp://ftp.iana.org/in-notes/iana/assignments/media-types/>. + +# MIME type Extension +application/mac-binhex40 hqx +application/mac-compactpro cpt +application/msword doc +application/pdf pdf +application/postscript ai eps ps +application/rtf rtf +application/x-bcpio bcpio +application/x-bzip2 bz2 +application/x-csh csh +application/x-gtar gtar +application/x-gzip gz tgz +application/x-kword kwd kwt +application/x-kspread ksp +application/x-kpresenter kpr kpt +application/x-kchart chrt +application/x-latex latex +application/x-sh sh +application/x-shar shar +application/x-shockwave-flash swf +application/x-tar tar +application/x-tcl tcl +application/x-tex tex +application/x-texinfo texinfo texi +application/x-troff t tr roff +application/x-troff-man man +application/zip zip +audio/mpeg mpga mp2 mp3 +audio/x-aiff aif aiff aifc +audio/x-wav wav +image/gif gif +image/ief ief +image/jpeg jpeg jpg jpe +image/png png +image/tiff tiff tif +text/plain asc txt +text/rtf rtf +text/sgml sgml sgm +text/xml xml +video/mpeg mpeg mpg mpe +video/x-msvideo avi +text/html html htm ++
+
If the file can be found or has the wrong format, Sylpheed will assume +the default MIME type for all the attachments: application/octet-stream. +In such a case, the recipients mail client may not know what application +to use to view the attachment. +
+
When opening an attachment (select the attachment, right click and select +Open) Sylpheed uses one of the following methods to determine +the application to launch: +
+
+
The binding of the applications to each MIME type is defined in the +mailcap file. The systeme wide file is /etc/mailcap, +while the user file is $HOME/.mailcap. +
+
In the mailcap file, there is one definition per line, big lines +can be broken by escaping the newline with a \ character, +the first element of the line is the MIME type, then a semi-colon, +(;), and finally the application to launch. +The application part (right side of the semi-colon) can contain several +shell commands separated by an escaped semi-colon (\;) and +the %s string is replaced by the name of the file when +launching the command. +
+
Following is a typical mailcap file (an extract of mine): +
+
+ +image/*; ee %s + +video/mpeg; gtv %s +video/*; xanim %s + +application/pdf; xpdf %s + +text/html; dillo %s ++
+
+