Propiedad Body vacía leyendo correos o emails con delphi e Indy

El motivo es porque el correo está codificado con encapsulación MIME-encoded text. Debebemos de leer el contenido que viene en varias partes y formar una cadena única

Ejemplo delphi:
---------------------------
nota: requiere el use TIdText;

for x := 0 to TheMsg.MessageParts.Count - 1 do begin 
      if TheMsg.MessageParts.Items[x] is TIdText then 
             BodyMsg := BodyMsg+ TIdText(TheMsg.MessageParts.Items[x]).Body.Text; 
end; 





Advanced Delphi Programming 

» Indy 9 Components

TIdText

Thu, 07 Jul 2011 | Indy 9 Components

Encapsulates a MIME-encoded text message part. TIdText = class(TIdMessagePart) Class Hierarchy

TCollectionltem TIdMessagePart TIdText [CI

Unit

IdMessage [CI TIdText Members Properties

Body

Textual content of the message part. Methods

^Assign Create

Copy the property values of an object instance. Constructor for the collection item.

^ Destroy Frees the object instance.

Legend

^virtual

Description

TIdText is a TIdMessagePart [C] descendant that encapsulates a MIME textual message part. TldAttachment [C] and TIdText are Created with Doc-O-Matic 2 donated to Project JEDI. Commercial license available from the Doc-O-Matic site.

used as collection items in a TldMessageParts [C] collection.

TldText provides the Body [C] property to represent the textual content of the message part. See Also

TldMessagePart[C], Technical Support [CI

Textual content of the message part. property Body: TStrings; Description

Body is a TStrings property that represents the textual content of the MIME message part. Body will be populated with the values from a valid TStrings instance supplied in the Create [C] constructor. Body may also be updated using inherited properties and methods from TStrings, like Text and Add.

See Also

TldText.Create [C]

fuente: https://www.delphipower.xyz/indy9/tidtext.html