When receiving a Delta Chat message, the client could strip unnecessary headers.
It can absolutely strip the autocrypt header from CC-to-self messages, but it could also strip
received-by and different spam-filter headers and only keep
It could also strip autocrypt headers from received messages, but this should probably have a config option, as it may cause problems when using multiple clients with the same account.
A message which is only a single word can be a message that needs more than 1 kb.