In message , Lewis
writes:
In message Mayayana
wrote:
"Lewis" wrote

| And there are many ways (countless ways) to send attachments. Many of
| them are entirely transparent to the user, so without digging they may
| have no idea how they are sent or what metadata is preserved.

You seem to just make things up on the spot. There
are not "many" ways to send attachments in email.

Yes there are.

Indeed. Some of which most modern email/news software doesn't know
about: for example, I can embed an attachment at any point within an
email, and someone else using the same software will see what I sent,
but someone using most other software will see the text I typed before
the attachment, then two attachments - the one I embedded being one, and
the text that came after being the other. [Most modern softwares
_always_ put attachments at the end, perhaps putting a _link_ (often
"cid:") in the body if they want to make it _appear_ that the attachment
isn't at the end.]

There's a format. All attachments are base64 encoded.

No, that is not true *at all*.

UUE was the other common encoding; it used to be the default, on the
basis that you didn't use MIME/base64 unless you knew the recipient
could decode it, but all clients could handle UUE. (Nowadays, most
clients _can't_ handle UUE!)

Any metadata is in the attached file. There's
no metadata sent in the email.

FSVO of metadata. The filnane (and extension) is metadata and is in the
email.

And maybe the size - and sometimes a type indicator. But in the vast
majority of cases, no dates. (Interesting to read from another poster
that there _is_ a mechanism for those to be included, but that he's
never seen it used.)
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Lucy Worsley takes tea in Jane Austen's Regency Bath. - TV "Choices" listing,
RT 2017-5-27