>>> "AS" == Adam Sjøgren <asjo@koldfront.dk> writes:

> Andreas writes:
>> On Feb 11 2019, Adam Sjøgren <asjo@koldfront.dk> wrote:
>> 
>>> It worked when I tried, as I showed.
>> 
>> It works for me when sent through my primary MTA, but not when sent
>> through an alternative MTA.  Either it depends on the MTA, or
>> sendmail/postfix handles it correctly, but smtpmail-send-it doesn't.

> Ok, I use ... [looks it up]... 'message-send-mail-with-sendmail, and my
> local MTA (providing /usr/sbin/sendmail) is Postfix 3.3.2, the receiving
> MTA in my test is Postfix 3.1.8.

Well I gave it a try 

I switched from 
(setq feedmail-buffer-eating-function 'feedmail-buffer-to-smtpmail
to 


(setq feedmail-buffer-eating-function 'feedmail-buffer-to-sendmail)

And did what you did but then I obtain 

sendmail: fatal: oub(1000): No recipient addresses found in message header
postdrop: warning: stdin: unexpected EOF in data, record type 78 length 76
postdrop: fatal: uid=1000: malformed input


Any ideas?