Ask for the account password before minting an app password, and keep
sessions the proxy checks from writing the account's own registry objects,
so a session left open on someone else's machine cannot take a credential
away from it. The password is compared with what the session holds; Stalwart
is asked only when 2FA moved the session onto an app password.
Serve attachments and proxied images with no-store on a device that is not
the person's own. Give files from a winmail.dat only the types the server
would show inline. Strip direction controls from sender and attachment
names and from saved filenames.
On signing out, send what is inside its undo window, then close every
composer, so the next person to sign in does not find the last one's draft.
Group sessions by the account Stalwart names and its server, so "sign out
other sessions" also reaches a session opened as a bare or differently
cased username.
Outlook sending in Rich Text packs every attachment into one TNEF blob.
Every other client shows a single unopenable winmail.dat, and the files
inside it are gone as far as the reader is concerned -- which is a
decoding problem rather than a mail one.
Written from the published format: a signature, a key, then a flat run of
attributes, each one a level byte, a 32-bit id carrying its own type, a
length, the data and a checksum. Attachments are delimited by
attAttachRenddata rather than named, which is why the parse is a small
state machine.
The MAPI property stream inside attAttachment is read for two properties:
the long filename and the MIME type. attAttachTitle carries an 8.3 name,
so a file that arrived as "Quarterly Report Final.docx" is QUARTE~1.DOC
there and correct here. The stream stops at a named property (id >=
0x8000) rather than guessing past it, since those carry a GUID before
their value and nothing after one can be trusted to stay aligned.
Decoded in the browser, on request. The server never sees the contents and
has nowhere to keep a decoded copy; doing the work on sight would spend
the bandwidth whether or not anybody wanted what is inside.
A blob that goes wrong part-way through keeps what was read before that
point, whether it ran out or the checksum stopped matching. Half the
attachments beats none: the alternative is a reader who can see the file
is there and cannot have it. The original stays attached either way.
The message body is deliberately not decoded. TNEF can also carry it as
compressed RTF, which is a second format again for a body the reader
already has in plain text or HTML nine times in ten.
The mock now sends one, built by its own encoder rather than by the
parser's fixtures, so the two are independent implementations of the same
description.