Viktor Dukhovni:
> On Thu, Jun 23, 2022 at 05:46:50PM +0530, Burn Zero wrote:
>
> > Thank you all and to Wietse Venema. You are right, the issue is with
> > the client email system. When checked in their system, the email size
> > is 17 MB and while exporting and saving that message, it becomes
> > around 47 MB.
>
> Perhaps some na?ve user or mail user agent is choosing quoted-printable
> rather than base64 for encoding large binary attachments. That would
> tend to produce roughly 2-3x expansion, because non-ASCII octets encode
> to 3 bytes (=nn hex encoding). With base64 the expansion is only ~35%.
I have seen that happen with the application/pdf content type.
Mis-use of quoted-printable has other problems, too. Quoted-printable
can produce inconsistent results when the sender and receiver systems
use different end-of-line conventions (for example, the native
'text' line break is two bytes or one, CRLF or LF). This changes
the length of the output file, and invalidates byte offsets in
decoded PDFs making them unreadable.
Wietse
