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From

property From: TIdEmailAddressItem read write;

Example​

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

  Msg.From.Address := 'integration@example.invalid';
  Msg.From.Name := 'Velox Integration';
end;

Usage​

Aliases the first FromList item and creates a blank item merely when read from an empty list, with SMTP sender fallback implications.

Additional Technical Info​

From is an alias for the first item of FromList, not a separately owned sender. It returns a borrowed TIdEMailAddressItem owned by that list.

Reading has a mutation side effect​

If FromList is empty, the getter calls FromList.Add before returning item zero. Merely evaluating Msg.From, Msg.From.Address or Msg.From.Text changes FromList.Count from zero to one and creates a blank owned item. Code that uses an empty list as a state signal must account for this.

Assigning another address item calls GetFrom.Assign(value): it creates item zero when necessary and copies only the source Address and Name. It does not replace the object. Nil assignment is not guarded.

GenerateHeader encodes the entire FromList, not just this alias. For this header only, Indy's encoder handles a missing display name by assigning Name := Address on the live item before encoding. Generation therefore permanently changes blank-name author items and usually emits a quoted display name plus the same address. Multiple items can appear in From, while this property continues to expose only the first.

Indy's default SMTP path chooses Sender.Address for the MAIL FROM envelope; if blank, it reads From.Address. That fallback can trigger the blank-item side effect. Header author and SMTP envelope sender remain separate concepts, and custom send overloads can provide another envelope sender.

ProcessHeaders repopulates FromList from the raw From header and decodes display names. ClearHeader clears the whole list, invalidating a retained From item. NoEncode does not project changes into raw headers.

The example uses a reserved .invalid address and was source-reviewed only; it did not send mail.

External references

Created 2026-07-15