As a general thing any .[*+] match is suspect. An often useful trick is to use a negative lookahead match to nibble one character at a time:

my $str = "Send it to bob.sled\@gmail.com. Don't send it to ski.guy\@y
+ahoo.com.";

print "$1\n" if $str =~ /(( (?!\.\s). )+ \.\s)/x;
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Prints:

Send it to bob.sled@gmail.com.
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