If multiple attachments have the same filename, only one is forwarded

[jwhitlock]

Attachments are indexed in a dictionary by filename:

fx-private-relay/emails/views.py

Lines 782 to 785 in 04cfa86

	att_name, att = (
	_get_attachment(part)
	)
	attachments[att_name] = att

If two attachments have the same filename, then the last one "wins".

The filename is optional, so if multiple attachments have no filename, the last one "wins" as well.

We can fix this by changing attachments to a different data structure, such as a list of (filename, data) tuples (or even (filename, mimetype, data)) tuples. We could also start by counting the number of parts in the incoming message versus the outgoing message, to see how significant the issue is.