From is a TIdEMailAddressItem property that identifies the original author of the message. From is updated using name and address token values found in the RFC 2822 message header "From:" for received messages. 

When creating a new message, values must be assigned to properties in the From component prior to transmission. 

Use the following properties to get or set the values for the TIdEMailAddressItem: 

FromList is used when reading or writing the value for the From property. The From property accesses the initial TIdEmailAddressItem address in the FromList property. 

From may not contain the same value as Sender when a message is forwarded.

TIdEMailAddressItem 

TIdMessage.Sender 

TIdMessage.FromList