Getting the raw base64 content out of an attachment in Indy?

Question

So I have an attachment on my incoming Pop3 message, Msg.MessageParts.Items[msgpart] as TidAttachmentFile but, is it possible to get the content of this attached file in the format specified by Msg.MessageParts.Items[msgpart].ContentTransfer (so base64 ascii) instead of creating a temp file, calling SaveToFile, and then re-reading the file and re-connverting back to base64?

Answer 1

If TIdMessage.NoDecode is set to False, then no, it is not possible. When NoDecode is False, TIdMessageClient decodes the email as it is being read off the socket and places decoded binary data into attachment objects. The only way to get the original base64 data is to set TIdMessage.NoDecode to True and parse the raw email data manually (it is stored as-is in the TIdMessage.Body) as you would effectively be disabling TIdMessageClient's entire decoding system.

On the other hand, if you just want to avoid the temp file, you can use the TIdMessage.OnCreateAttachment event to have Indy create TIdAttachmentMemory objects instead of the default TIdAttachmentFile objects. The base64 will still be auto-decoded and stored as binary in the attachment, but at least the attachment would be solely in memory so your re-encode would be faster.