Comment # 2 on bug 1041206 from Peter Wullinger

> User "mail" (specified in one of the Makefiles) does not exist.

Looks like the fix is is already in server:mail as of
https://build.opensuse.org/request/show/504846

Requires(pre):  %fillup_prereq permissions
%if 0%{?suse_version} >= 1330
BuildRequires:  group(mail)
BuildRequires:  user(mail)
Requires(pre):  user(mail)
Requires(pre):  group(mail)
%endif