Sometimes standards are very complex and not very flexible, but they are adopted by a large number of companies, so they should be used to conform to the de facto status of the world.
Outlook gives the users the capability to use their own languages. This is very friendly, but it can cause a lot of collaterl problems, for example the italian version of outlook uses the "R:" prefix when the user replies to a mail. Since the mail client is outlook this is not a problem, but if the counterpart uses a different mail client it can cause thread sorting and visualization problems.
For example it's not strange to see a mail message with the subject like the following:
Re: R: R: R: R: R: R: R: Re:R: R: R: R: R: R: R: R: Re: R: R: R: R: R: R: R: Saluti.
The RFC 2822 – Internet Message Format defines the rules for Internet message format
3.6.5. Informational fields
The informational fields are all optional. The "Keywords:" field contains a comma-separated list of one or more words or quoted-strings. The "Subject:" and "Comments:" fields are unstructured fields as defined in section 2.2.1, and therefore may contain text or folding white space.
subject = "Subject:" unstructured CRLF
comments = "Comments:" unstructured CRLF
keywords = "Keywords:" phrase *("," phrase) CRLF
These three fields are intended to have only human-readable content with information about the message. 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. The "Comments:" field contains any additional comments on the text of the body of the message. The "Keywords:" field contains a comma-separated list of important words and phrases that might be useful for the recipient.
To conform with the standard you have only to execute few steps:
- Launch Outlook
- Go to Tools->Options
- Select the "mail format" tab
- Select the international options button
- select all the checkboxes in this window
See you soon.