Every message ihasmail sent set cc, bcc and replyTo to null when unused, and
inReplyTo/references likewise on a new message. Stalwart parses those
properties with try_into_address_list, which returns None for null, and the
create is rejected outright:
if let Some(addresses) = value.try_into_address_list() { ... }
else { response.invalid_property_create(id, header); continue 'create; }
So every send failed with "Invalid property or value.", new messages and
replies alike, regardless of attachments or signature. The mock server
accepts anything, which is why this only showed up against a real server.
Empty header properties are now omitted. On a create there is no previous
value to clear, so null was never needed - only the properties actually being
set belong in the object.
buildEmailObject is exported so the shape can be tested directly, with a
regression test that no property is ever null.
jcoffey-dev
eadec49b4f