What does "Convert ... upon sending" mean?

[Paul Gilmartin]

On 2019-04-21, at 23:53:34, Cameron Simpson wrote:

>>>> 3  3                   �   �   �   �   c   l   t   �   C   L   T   3
>>> 
>>> How are those listings obtained? Might the thing presenting those listings be interpreting the iso8859-5 data as the local character encoding and thus misrendering?
>>> 
>> They're the Unicode "Replacement Character":
>>   https://www.fileformat.info/info/unicode/char/fffd/index.htm
>>   HTML Entity (hex)	�
>>   UTF-8 (hex)	0xEF 0xBF 0xBD (efbfbd)
> 
> Is the listing above the content of the attachment? Or the result of some dump tool?
> 
> Anything displayed on the terminal has been through various translations (including the terminal itself), and I was wondering if you were looking at your two outputs via different mechanisms.
>  
OK.  I need to use "some dump tool" because my retinas aren't sensitive
to magnetic domains on a disk.  So, I dragged the attachment once from my
Sent folder and once from Inbox to desktop.  Then:

510 $ od -tx1 *sent.txt | head -16
0000000    20  20  20  20  48  6f  73  74  3a  20  49  42  4d  2d  31  30
0000020    34  37  20  20  6f  75  74  70  75  74  3a  20  66  72  6f  6d
0000040    5f  49  53  4f  38  38  35  39  2d  35  0a  20  20  20  20  20
0000060    20  20  20  20  20  30  20  20  31  36  20  20  33  32  20  20
0000100    34  38  20  20  36  34  20  20  38  30  20  20  39  36  20  31
0000120    31  32  20  31  32  38  20  31  34  34  20  31  36  30  20  31
0000140    37  36  20  31  39  32  20  32  30  38  20  32  32  34  20  32
0000160    34  30  0a  20  20  20  20  20  20  20  20  20  20  30  20  20
0000200    31  30  20  20  32  30  20  20  33  30  20  20  34  30  20  20
0000220    35  30  20  20  36  30  20  20  37  30  20  20  38  30  20  20
0000240    39  30  20  20  61  30  20  20  62  30  20  20  63  30  20  20
0000260    64  30  20  20  65  30  20  20  66  30  0a  0a  20  20  20  30
0000300    20  20  30  20  20  20  20  20  20  20  20  20  20  20  20  20
0000320    20  20  30  20  20  20  40  20  20  20  50  20  20  20  60  20
0000340    20  20  70  20  20  20  20  20  20  20  20  20  20  20  a0  20
0000360    20  20  b0  20  20  20  c0  20  20  20  d0  20  20  20  e0  20

... notice the 5 non-ASCII octets, a0, b0, c0, d0, and e0 in the last
two lines.  After a trip through AOL:

512 $ od -tx1 *SCII.txt | head -17
0000000    20  20  20  20  48  6f  73  74  3a  20  49  42  4d  2d  31  30
0000020    34  37  20  20  6f  75  74  70  75  74  3a  20  66  72  6f  6d
0000040    5f  49  53  4f  38  38  35  39  2d  35  0a  20  20  20  20  20
0000060    20  20  20  20  20  30  20  20  31  36  20  20  33  32  20  20
0000100    34  38  20  20  36  34  20  20  38  30  20  20  39  36  20  31
0000120    31  32  20  31  32  38  20  31  34  34  20  31  36  30  20  31
0000140    37  36  20  31  39  32  20  32  30  38  20  32  32  34  20  32
0000160    34  30  0a  20  20  20  20  20  20  20  20  20  20  30  20  20
0000200    31  30  20  20  32  30  20  20  33  30  20  20  34  30  20  20
0000220    35  30  20  20  36  30  20  20  37  30  20  20  38  30  20  20
0000240    39  30  20  20  61  30  20  20  62  30  20  20  63  30  20  20
0000260    64  30  20  20  65  30  20  20  66  30  0a  0a  20  20  20  30
0000300    20  20  30  20  20  20  20  20  20  20  20  20  20  20  20  20
0000320    20  20  30  20  20  20  40  20  20  20  50  20  20  20  60  20
0000340    20  20  70  20  20  20  20  20  20  20  20  20  20  20  ef  bf
0000360    bd  20  20  20  ef  bf  bd  20  20  20  ef  bf  bd  20  20  20
0000400    ef  bf  bd  20  20  20  ef  bf  bd  20  20  20  ef  bf  bd  0a


... each non-ASCII octet has been changed to Replacement, "ef  bf  bd".

> Can you deliver the same message attachments through 2 SMTP services (AOL and another) ...
>  
I can use 3 SMTP servers: AOL, Yahoo, and GMail.  The problem occurs with
AOL, not Yahoo or GMail.  The behavior does not depend on which IMAP server
I use with a viewer.  I blame AOL's SMTP.

Thanks for your advice,
gil