[Mimedefang] RFC2822.pm: uninitialized value $msgid_header in concatenation

[Max A.]

Hello.

I have mimedefang running on Rocky Linux 8.7. After upgrading to version 
3.2 (mimedefang-3.2-1.el8.x86_64 from EPEL) I see this error in the logs:

mimedefang-multiplexor[141566]: A03501F354: Worker 0 stderr: Use of 
uninitialized value $msgid_header in concatenation (.) o
mimedefang-multiplexor[141566]: A03501F354: Worker 0 stderr: r string at 
/usr/share/perl5/vendor_perl/Mail/MIMEDefang/RFC282
mimedefang-multiplexor[141566]: A03501F354: Worker 0 stderr: 2.pm line 50.

without additives from syslog:

Use of uninitialized value $msgid_header in concatenation (.) or string 
at /usr/share/perl5/vendor_perl/Mail/MIMEDefang/RFC2822.pm line 50.

This happens in the subroutine:

sub gen_date_msgid_headers {
     my ($msgid_header) = @_;
     return "Date: " . rfc2822_date() . "\n" . $msgid_header; # <--- line 50
}

This subroutine is called from MIMEDefang.pm several times, everywhere 
as follows:

$body .= Mail::MIMEDefang::RFC2822::gen_date_msgid_headers();

No values are passed to the gen_date_msgid_headers routine, maybe that's 
why the $msgid_header variable is not initialized?

My knowledge of perl is not very good and there may be another reason, 
but the errors in the log say that something is going wrong.