>>
>>
>> Er, you seem to be attaching recipient information to the MAIL FROM
>> command which makes no sense at all. The AUTH= parameter is supposed
>> to give the authenticated identity of the original message sender
>> (which may of course be different from the return path); it isn't
>> something you can randomly invent.
>>
>> Also, the AUTH= parameter needs to be encoded as an xtext and you
>> don't appear to have addressed that requirement.
>
> Maybe you're correct but cyrus 2.1.15 needs an "AUTH=<name>" in the way I
> described above to allow deliver mail directly to the users subfolders. The
> <name> must be a username that is allowd to post to that mailbox.
Which means you have to allow anonymous posting to this mailbox. See cyradm(1).