On 10/03/2017 05:34 PM, Bill Maidment wrote:
> Hi
> All my upgrades to SL 7.4 worked OK, until the mail server restarted using sendmail instead of postfix. It seems that the upgrade switched off postfix in systemd and instead switched on sendmail.
> A bit disconcerting.
I had this issue as well with CentOS 7.4, so it's an upstream bug and 
would need to be reported upstream.  It was more than just disconcerting 
here, as sendmail didn't know how to deliver to Scalix (which we use, 
and which requires 'sendmail' even though I have it configured with 
postfix).  So I had some email delivery issues, and some bounces, during 
the time sendmail was active.

I hadn't looked closely enough to track where the bug actually is; it's 
probably an assumption in the sendmail package's %post scriptlet, but I 
reserve the right to be wrong.

I posted a message to the CentOS list afterwards on the subject, but got 
no replies.  I figured someone else would run up against it, and you did.