Re: Sendmail and DKIM for bounce messages?

om@iki.fi (Otto J. Makela) wrote:

I've even considered hard-wiring these mail recepients to only use
IPv4, but of course doing this is painful since M365 keeps shifting
around so much.

I actually just did this, inserted into mailertable a line like

client.domain esmtp:[ipv4-address-of-their-m365-mx]

and then ran

/usr/lib/sendmail -qRclient.domain

which nicely transferred the outstanding queue of messages from
mailer-daemon to their server. "Of course" they'll accept unsigned
messages if you are connecting over IPv4 :-/

Unfortunately, this horrible kludge is not something one really can
leave in place for an extended period.
--
   /* * * Otto J. Makela <om@iki.fi> * * * * * * * * * */
  /* Phone: +358 40 765 5772, ICBM: N 60 10' E 24 55' */
 /* Mail: Mechelininkatu 26 B 27,  FI-00100 Helsinki */
/* * * Computers Rule 01001111 01001011 * * * * * * */