my $t = "\t";
    my $msg = <<"END_OF_BODY";

The number of SKUs that have been flagged as DeleteMe is greater than 
+the
threshold of $threshold and thus Manager approval is required.

Here is the list of SKUs and their counts:

PLANNERCODE${t}DEALER${t}COUNT
=================================

@{[ join("\n", map {join("\t",@$_)} @output_array) ]}

END_OF_BODY
[download]

The here-doc construct <<"END_OF_BODY"interpolates as within double quotes. The @{ } thingy dereferences (even between double quotes) an anonymous array, which is - inside that - constructed with [ ] (see perlref). To build that anonymous array, the content must first be expanded - and here's where the magic is: it can be any valid expression which returns a list, up to e.g. a complex do BLOCK statement.

Note that '\t' is not expanded into a <Tab> in here-docs. You have to stuff that char into a variable first. The ${t} construct serves to disambiguate from e.g. $tCOUNT.

But generally, when you need to do strange and funny things in here-docs, formats are better, provided you have a somehwat regular data set (i.e. a fixed number of elements in an array). format templates are static, though you could also whip them up on the fly using formline and the accumulator (see perlvar).

But that, again, also means doing funny things.

When you reach the limits of formats, use some templating solution.

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}