KMail/sendmail problem

I'm running Fedora-24(beta)/KDE, and sendmail/email (through KMail) is failing. When I try to send email I get the warning "Failed to transmit message", and journalctl has the entry "sendmail.service: PID file /run/sendmail.pid not readable (yet?) after start: No such file or directory". I've checked, and sendmail.pid is in place: ================== [tim@william ~]$ sudo cat /run/sendmail.pid 2829 /usr/sbin/sendmail -bd -q1h ================== Googling for the journalctl entry, I see people have been encountering this problem for years. But I haven't seen any solution suggested. Several of the comments suggest that it is a systemd problem. If anyone can offer advice, or even elucidation, I should be most grateful. Ps I posted this to fedora.general, and was advised to post it to fedora-testing. When I sent it there I was advised (by Ed Greshko) to send it here, since he thought it was a KMail problem, rather than systemd. I have no problem sending SMTP mail with Thunderbird and Evolution. -- Timothy Murphy gayleard /at/ eircom.net School of Mathematics, Trinity College, Dublin