Rather than split'ing the line on spaces use a look-ahead to do it at a point followed by the text "address".

knoppix@Microknoppix:~$ perl -E '
> $line = qq{address 6433 main st address 6434 main st address 6435 ma
+in st\n};
> chomp $line;
> say for split m{(?=address)}, $line;'
address 6433 main st 
address 6434 main st 
address 6435 main st
knoppix@Microknoppix:~$
[download]

I hope this is helpful.

Update: A more complete solution catering for the two header lines and split'ing at a space that is followed by the text "address".

knoppix@Microknoppix:~$ perl -Mstrict -Mwarnings -E '
> open my $inFH, q{<}, \ <<EOF or die $!;
> This is the list of address
> here are the addreses
> address 6433 main st address 6434 main st address 6435 main st
> EOF
> 
> print scalar <$inFH> for 1 .. 2;
> my $line = <$inFH>;
> chomp $line;
> say for split m{\s+(?=address)}, $line;'
This is the list of address
here are the addreses
address 6433 main st
address 6434 main st
address 6435 main st
knoppix@Microknoppix:~$
[download]