Skip to main content

CharSet

property CharSet: string read write;

Example​

procedure ConfigureUtf8Body;
var
  Msg: TIdMessage;
begin
  Msg := Email;
  if Msg = nil then Exit;

  Msg.ContentType := 'text/plain';
  Msg.CharSet := 'utf-8';
end;

Usage​

Stores the unvalidated MIME charset label used for body conversion and Content-Type generation, with unknown labels silently falling back to 8-bit handling.

Additional Technical Info​

CharSet is the message-level MIME charset label, such as utf-8 or us-ascii. Its setter is a direct String assignment: no normalization, registry lookup or support check occurs at assignment time.

Normal Body serialization calls Indy's CharsetToEncoding(CharSet). That helper first offers a global custom-encoding callback, then tries the known charset/code-page mapping. Unknown or unavailable labels do not normally raise; Indy silently returns its 8-bit fallback, even though the declared label can still be written to the message. A typo can therefore produce bytes that do not match the advertised charset.

Interaction with ContentType​

Assigning ContentType can change this property:

  • an embedded charset parameter is removed from stored ContentType and replaces CharSet;
  • text media with no embedded charset sets us-ascii only when CharSet was previously empty;
  • assigning empty ContentType stores text/plain and resets CharSet to us-ascii.

Set ContentType first and CharSet second when an explicit charset must win. Conversely, a later ContentType assignment containing a charset overwrites the earlier value.

ProcessHeaders extracts the raw Content-Type charset and defaults a missing text charset to us-ascii. GenerateHeader writes the current label as the message Content-Type parameter for ordinary message-level output. If it is empty and the type is text, generation uses us-ascii locally without updating this field.

Single-part MIME takes content headers from its one part, whose own CharSet can differ. Automatic ConvertPreamble copies this message value into the appended TIdText. Header display names and Subject use Indy's separate platform-default header charset selection, not this property.

NoEncode bypasses typed header/body generation. The example is source-reviewed only; no byte conversion or mail operation ran.

External references

Created 2026-07-15