[Exim] Upgraded to exim 4.34 - but..!

I am using exim to distribute mail to several internal and external mailservers
on my own and other instutions.
Just update from 3.16 on redhat - which worked fine, to version 4.34 on redhat
8.
I ran the conversion scrips for the configure file, and it seems ok.

The new server ran just fine yesterday for two hours, and then it started to
claim relaying not permitted.

the acls seems ok

any ideas ???