Error emails sent with empty "From"

See also:
https://rt.bestpractical.com/SelfService/Display.html?id=37571

Some errors are notified via email, e.g. something like

xyz@xyz.com attempted to create a ticket via email in the queue XYZ;
you might need to grant ‘Everyone’ the CreateTicket right.

That error message seems to go to $OwnerEmail, but with an empty “From:”
header line, and this may cause issues (bounces?) at some mail gateways
(e.g. my own email processor complains about it).

Though the real bug may be that “Queue” is not set before calling
CheckACL() (so there is no CorrespondAddress), I propose the simple
patch below.

Cheers, Paul

— /usr/share/request-tracker4/lib/RT/Interface/Email.pm.bak 2022-07-03 18:09:25.000000000 +1000
+++ /usr/share/request-tracker4/lib/RT/Interface/Email.pm 2023-03-26 06:20:34.043733647 +1100
@@ -689,7 +689,7 @@
sub MailError {
my %args = (
To => RT->Config->Get(‘OwnerEmail’),

  •    From        => RT->Config->Get('CorrespondAddress'),
    
  •    From        => ( RT->Config->Get('CorrespondAddress') || RT->Config->Get('OwnerEmail') ),
       Subject     => 'There has been an error',
       Explanation => 'Unexplained error',
       MIMEObj     => undef,
    

As per RT ticket 37571… this issue was my misconfiguration:
should have had some $CorrespondAddress in my setttings,
on my machine it would be in file
/etc/request-tracker4/RT_SiteConfig.d/50-debconf.pm