37.13 Display of Messages

Rmail reformats the header of each message before displaying it for the first time. Reformatting hides uninteresting header fields to reduce clutter. You can use the t command to show the entire header or to repeat the header reformatting operation.

t

Toggle display of complete header (rmail-toggle-header).

Reformatting the header involves deleting most header fields, on the grounds that they are not interesting. The variable rmail-ignored-headers holds a regular expression that specifies which header fields to hide in this way—if it matches the beginning of a header field, that whole field is hidden. However, the variable rmail-nonignored-headers provides a further override: a header matching that regular expression is shown even if it matches rmail-ignored-headers too.

Rmail saves the complete original header before reformatting; to see it, use the t command (rmail-toggle-header). This discards the reformatted headers of the current message and displays it with the original header. Repeating t reformats the message again, which shows only the interesting headers according to the current values of those variable. Selecting the message again also reformats it if necessary.

One consequence of this is that if you edit the reformatted header (using e; see section Editing Within a Message), subsequent use of t will discard your edits. On the other hand, if you use e after t, to edit the original (unreformatted) header, those changes are permanent.

When the t command has a prefix argument, a positive argument means to show the reformatted header, and a zero or negative argument means to show the full header.

When the terminal supports multiple fonts or colors, Rmail highlights certain header fields that are especially interesting—by default, the ‘From’ and ‘Subject’ fields. The variable rmail-highlighted-headers holds a regular expression that specifies the header fields to highlight; if it matches the beginning of a header field, that whole field is highlighted.

If you specify unusual colors for your text foreground and background, the colors used for highlighting may not go well with them. If so, specify different colors by setting the variable rmail-highlight-face to a suitable face. To turn off highlighting entirely in Rmail, set rmail-highlighted-headers to nil.

You can highlight and activate URLs in incoming messages by adding the function goto-address to the hook rmail-show-message-hook. Then you can browse these URLs by clicking on them with Mouse-2 (or Mouse-1 quickly) or by moving to one and typing C-c <RET>. See section Activating URLs.