Originally posted by: dieter_mosbach

The version 1.4.2.1 available in AIX toolbox is from 2006, thirteen years ago...

Stable release is 1.11.4 (March 13, 2019; 2 months ago)

mutt 1.4 does not support html-mails like
mutt -e "set content_type=text/html"     test@invalid -s "subject" -a pic.png  < test.html
mutt -e "my_hdr Content-Type: text/html" test@invalid  -s "subject" -a pic.png < test.html

Or is there another solution to send HTML-mails?

Originally posted by: AyappanP

We have sendmail in AIX Toolbox. 

https://www.ibm.com/developerworks/aix/library/aix-toolbox/alpha.html

Check whether it will satisfy your requirement. 

We will also try to update mutt to the latest level in the near future.