So far, however, the number of mail pieces lost to alternative bill-paying methods is too small to have any material impact on First-Class volume.
( ( So far ) ( , ( however ( , ( ( ( the number ) ( of ( ( mail pieces ) ( lost ( to ( alternative ( bill-paying methods ) ) ) ) ) ) ) ( ( ( is ( too small ) ) ( to ( have ( ( any ( material impact ) ) ( on ( First-Class volume ) ) ) ) ) ) . ) ) ) ) ) )
(ROOT (S (ADVP (IN So) (RB far)) (, ,) (ADVP (RB however)) (, ,) (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NP (NN mail) (NNS pieces)) (VP (VBN lost) (PP (TO to) (NP (JJ alternative) (JJ bill-paying) (NNS methods))))))) (VP (VBZ is) (ADJP (RB too) (JJ small)) (S (VP (TO to) (VP (VB have) (NP (NP (DT any) (NN material) (NN impact)) (PP (IN on) (NP (NNP First-Class) (NN volume)))))))) (. .)))
Occasionally mail is lost but not often 
( ( Occasionally mail ) ( is ( lost ( but ( not often ) ) ) ) )
(ROOT (S (NP (JJ Occasionally) (NN mail)) (VP (VBZ is) (VP (VBN lost) (PRN (CC but) (ADVP (RB not) (RB often)))))))