Scatter/Gather thoughts

by Johan Petersson

How to fix the broken Outlook reply behaviour

Have you ever used non-English versions of Microsoft Outlook or Outlook Express, communicated with such users via mail, or read such users' replies to Usenet or mailing list messages? An Internet user will find it hard to avoid doing at least the latter; even if you don't regularly read newsgroups and aren't subscribed to any mailing lists, those replies are common results when searching the web or Google Groups.

If so, you have probably been exposed to this particular broken behaviour. Localized versions of Outlook and Outlook Express prepends a language-specific prefix to mark message subjects in replies, e.g. AW: (Antwort, German and Dutch versions), SV: (Svar, Scandinavian versions), VS: (Vastaus, Finnish versions), and ODP: (Odpowied?, Polish versions). Microsoft has localized the reply prefix. Why is this a bug rather than a feature?

First of all, it's in violation of Internet standards (for Usenet) and recommended Internet practices (for mail). A mail or news client is expected to use Re: to indicate replies, not anything else. Despite the fact that it isn't part of the protocol per se, the reply indicator is no more localizable than header fields like Subject.

As far as I can tell there's no documentation covering this "extension" and no clients, including Microsoft's own, are able to deal with those prefixes correctly. This is what causes the most problems in practice, because unrecognized prefixes will accumulate in subject lines. After a few rounds of replies, message subjects gets very difficult to read and may even be truncated due to display or processing limits:

Re: SV: SV: SV: AW: SV: SV: All results from the

You may think localized reply indicators are desirable. That's a reasonable position. But if that's what you want, note that it doesn't make any sense to send a prefix based on your own language when replying. The indicator is for the benefit of people reading the replies you send, therefore a localized reply indicator must be based on the language of each individual recipient, not on that of the sender. A client with support for localized reply indicators would never send localized strings, it would just display them instead of Re: when presenting the message to the user.

Finally, there's the minor point that the translation is incorrect, at least for the languages I know well enough to tell the difference. Microsoft has plausible deniability here because a localized string is not necessarily a translation, but in this context Re is not short for reply. Citing RFC 2822:

The "Subject:" field is the most common and contains a short string identifying the topic of the message. When used in a reply, the field body MAY start with the string "Re: " (from the Latin "res", in the matter of) followed by the contents of the "Subject:" field body of the original message. If this is done, only one instance of the literal string "Re: " ought to be used since use of other strings or more than one instance can lead to undesirable consequences.

Undesirable and unfortunately almost unavoidable consequences of using older versions of Microsoft Outlook and Outlook Express (it was possible but nontrivial to fix). Client limitations is not a valid excuse any longer; current versions still do the wrong thing by default, but have an option for modifying the behaviour. Here's what you need to do (dialogs and option names are from the English version, but it shouldn't be too hard to find the equivalent options):

Outlook Express: go to Options... in the Tools menu, click the Send tab, International Settings..., and enable When replying to message always use English headers.

When replying to message always use English headers

Outlook: choose Options... in the Tools menu, click the Mail Format tab, then International Options..., and enable Use English for message headers on replies and forwards.

Use English for message headers on replies and forwards

Even with this change, at least some versions of Outlook and Outlook Express will use RE with an upper-case "E" instead of Re, but mail software will generally be able to cope with that inconsistency.

21 June, 2005