Just do exactly what I said, don't include the newlines you don't want: 
my $msg_body_1 = 
   "line 1\n" .
   "line 2\n" .
   "line3a  \t  \line3b\n" .
   "line4" .
   "\n\n"
;

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In reply to Re^3: Formatting Strings Without Interpolating Whitespace by JavaFan
in thread Formatting Strings Without Interpolating Whitespace by BJ_Covert_Action

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