Unknown filter action forward

[Jerome]

On Monday, August 7, 2023 5:59:12 P.M. MDT Peter Humphrey wrote:
> On Tuesday, 8 August 2023 00:28:20 BST Jerome wrote:
> > Ever since upgrading to Kmail 5.22.0, every time I start KDE I get an
> > Information dialog from the Mail Filter Agent
> > 
> >     Unknown filter action forward in filter rule XXXX
> > 
> > Except I don't have such an action in my filter rules.
> > 
> > This also happens with the latest Fedora 38.
> > 
> > Googling finds nothing useful for "Unknown filter action" KMail.
> > 
> > It only happens when KDE starts so it's an annoyance, but... any ideas?
> 
> Do you get your mails via POP3?

Yes, but KMail hasn't even been started when the message appears.