upsend pusend uspend supend psuend spuend upesnd puesnd uepsnd eupsnd peusnd epusnd usepnd suepnd uespnd euspnd seupnd esupnd pseund speund pesund epsund sepund espund upsned pusned uspned supned psuned spuned upnsed punsed unpsed nupsed pnused npused usnped sunped unsped nusped snuped nsuped psnued spnued pnsued npsued snpued nspued upensd puensd uepnsd eupnsd peunsd epunsd upnesd punesd unpesd nupesd pnuesd npuesd uenpsd eunpsd unepsd nuepsd enupsd neupsd penusd epnusd pneusd npeusd enpusd nepusd usenpd suenpd uesnpd eusnpd seunpd esunpd usnepd sunepd unsepd nusepd snuepd nsuepd uenspd eunspd unespd nuespd enuspd neuspd senupd esnupd sneupd nseupd ensupd nesupd psenud spenud pesnud epsnud sepnud espnud psneud spneud pnseud npseud snpeud nspeud pensud epnsud pnesud npesud enpsud nepsud senpud esnpud snepud nsepud enspud nespud upsedn pusedn uspedn supedn psuedn spuedn upesdn puesdn uepsdn eupsdn peusdn epusdn usepdn suepdn uespdn euspdn seupdn esupdn pseudn speudn pesudn epsudn sepudn espudn upsden pusden uspden supden psuden spuden updsen pudsen udpsen dupsen pdusen dpusen usdpen sudpen udspen duspen sdupen dsupen psduen spduen pdsuen dpsuen sdpuen dspuen upedsn puedsn uepdsn eupdsn peudsn epudsn updesn pudesn udpesn dupesn pduesn dpuesn uedpsn eudpsn udepsn duepsn edupsn deupsn pedusn epdusn pdeusn dpeusn edpusn depusn usedpn suedpn uesdpn eusdpn seudpn esudpn usdepn sudepn udsepn dusepn sduepn dsuepn uedspn eudspn udespn duespn eduspn deuspn sedupn esdupn sdeupn dseupn edsupn desupn psedun spedun pesdun epsdun sepdun espdun psdeun spdeun pdseun dpseun sdpeun dspeun pedsun epdsun pdesun dpesun edpsun depsun sedpun esdpun sdepun dsepun edspun despun upsnde pusnde uspnde supnde psunde spunde upnsde punsde unpsde nupsde pnusde npusde usnpde sunpde unspde nuspde snupde nsupde psnude spnude pnsude npsude snpude nspude upsdne pusdne uspdne supdne psudne spudne updsne pudsne udpsne dupsne pdusne dpusne usdpne sudpne udspne duspne sdupne dsupne psdune spdune pdsune dpsune sdpune dspune upndse pundse unpdse nupdse pnudse npudse updnse pudnse udpnse dupnse pdunse dpunse undpse nudpse udnpse dunpse ndupse dnupse pnduse npduse pdnuse dpnuse ndpuse dnpuse usndpe sundpe unsdpe nusdpe snudpe nsudpe usdnpe sudnpe udsnpe dusnpe sdunpe dsunpe undspe nudspe udnspe dunspe nduspe dnuspe sndupe nsdupe sdnupe dsnupe ndsupe dnsupe psndue spndue pnsdue npsdue snpdue nspdue psdnue spdnue pdsnue dpsnue sdpnue dspnue pndsue npdsue pdnsue dpnsue ndpsue dnpsue sndpue nsdpue sdnpue dsnpue ndspue dnspue upends puends uepnds eupnds peunds epunds upneds puneds unpeds nupeds pnueds npueds uenpds eunpds unepds nuepds enupds neupds penuds epnuds pneuds npeuds enpuds nepuds upedns puedns uepdns eupdns peudns epudns updens pudens udpens dupens pduens dpuens uedpns eudpns udepns duepns edupns deupns peduns epduns pdeuns dpeuns edpuns depuns upndes pundes unpdes nupdes pnudes npudes updnes pudnes udpnes dupnes pdunes dpunes undpes nudpes udnpes dunpes ndupes dnupes pndues npdues pdnues dpnues ndpues dnpues uendps eundps unedps nuedps enudps neudps uednps eudnps udenps duenps edunps deunps undeps nudeps udneps duneps ndueps dnueps endups nedups ednups denups ndeups dneups pendus epndus pnedus npedus enpdus nepdus pednus epdnus pdenus dpenus edpnus depnus pndeus npdeus pdneus dpneus ndpeus dnpeus endpus nedpus ednpus denpus ndepus dnepus usendp suendp uesndp eusndp seundp esundp usnedp sunedp unsedp nusedp snuedp nsuedp uensdp eunsdp unesdp nuesdp enusdp neusdp senudp esnudp sneudp nseudp ensudp nesudp usednp suednp uesdnp eusdnp seudnp esudnp usdenp sudenp udsenp dusenp sduenp dsuenp uedsnp eudsnp udesnp duesnp edusnp deusnp sedunp esdunp sdeunp dseunp edsunp desunp usndep sundep unsdep nusdep snudep nsudep usdnep sudnep udsnep dusnep sdunep dsunep undsep nudsep udnsep dunsep ndusep dnusep snduep nsduep sdnuep dsnuep ndsuep dnsuep uendsp eundsp unedsp nuedsp enudsp neudsp uednsp eudnsp udensp duensp edunsp deunsp undesp nudesp udnesp dunesp nduesp dnuesp endusp nedusp ednusp denusp ndeusp dneusp sendup esndup snedup nsedup ensdup nesdup sednup esdnup sdenup dsenup edsnup desnup sndeup nsdeup sdneup dsneup ndseup dnseup endsup nedsup ednsup densup ndesup dnesup psendu spendu pesndu epsndu sepndu espndu psnedu spnedu pnsedu npsedu snpedu nspedu pensdu epnsdu pnesdu npesdu enpsdu nepsdu senpdu esnpdu snepdu nsepdu enspdu nespdu psednu spednu pesdnu epsdnu sepdnu espdnu psdenu spdenu pdsenu dpsenu sdpenu dspenu pedsnu epdsnu pdesnu dpesnu edpsnu depsnu sedpnu esdpnu sdepnu dsepnu edspnu despnu psndeu spndeu pnsdeu npsdeu snpdeu nspdeu psdneu spdneu pdsneu dpsneu sdpneu dspneu pndseu npdseu pdnseu dpnseu ndpseu dnpseu sndpeu nsdpeu sdnpeu dsnpeu ndspeu dnspeu pendsu epndsu pnedsu npedsu enpdsu nepdsu pednsu epdnsu pdensu dpensu edpnsu depnsu pndesu npdesu pdnesu dpnesu ndpesu dnpesu endpsu nedpsu ednpsu denpsu ndepsu dnepsu sendpu esndpu snedpu nsedpu ensdpu nesdpu sednpu esdnpu sdenpu dsenpu edsnpu desnpu sndepu nsdepu sdnepu dsnepu ndsepu dnsepu endspu nedspu ednspu denspu ndespu dnespu
Note: these 'words' (valid or invalid) are all the permutations of the word upsend. These words are obtained by scrambling the letters in upsend.