4,91 9

NET~ORK WORKING GROUP ABHAY K. SHUSHAN

RFC "475 M~T-DH(;G
NIC #14919 MARCH 6, 1973
FTP AND NETWORK MAIL SYSTEM f<.uJ~ IS'I t(Itt. 71

This paper describes my underst~nding of tne results of ~he

Net~ork Xail system m e e t i n ~ SRI-APe on february 23, 1973, and the
implicat~onc for FTP (file TranGier protocol). There ~as ge ne r a l
agreement at the meeting that Iletwork nail function should be withi n
FTP.

FTP currently crcv id es two CO~Mands for handling mail. The I ~ A I L

cO~8and all oWs ~ user ~o send ma11 Via the TEL M~T conection (the 5e ~ v e r
collects t. n e n a i l ar. u o e t.e r -m ne s its en d byse;trcnine: for the cn a r a c t.e r
seq ue nee "c r: L r • CIt L F " I , 'l' h e ;'1L i ' L ( :':1 ail f j.l e) c 0 ;1', n and all 0 'Ii S a us e r t o
Send ffi1il Vi a ~he d a~ a connect ion (r~q u ires a user-FTF to han 6le ~ n ~
con n a nd cu t t.r s n s r c r a s n o r e e f .f ic a e n t. 2..3 s e rv e r ne eo no t s e arc n r o r ..l
s pe c a a L c na r a c ve r s e c ue n e ) ; Tl:e~e c on ria no s are b e a m; used t o Cl"C'l J.. C~
ne t.wor x ma iling facil i ties. Local l1"'ail and S liL'~SG progra ms n av e be e n
mod1!ied a t Ma n y sit e s to inclU Gc net~or~ nailing (e.g, USE H ~BO~1 a~
B13~1-1'E;~ ;EX a nc l-~AIL nc c t user at. ~UT-JJ:1CG).

The netwo~k n a i l s y s t ~ n should provide a facility WherebY users c a n

convenien tl y s e no r.e s S d ~ e s to o t.b e r ne t ',:ork use r S wn o na v e "n aii 0 % t; S ."
at one or ~ o r ~ h os ~s . It, is not r enUi~ed tha~ ~he m e s s a~e R or ~ail C ~
~ l i v e ~ e d i ~ re l l-~i ~ c. The n et~or~ mail sYs"e~ is not an int er ~ct 1 v ~
. n t c r - c on so le c o~~ un icatio~ ~ ~cility, but it ~ a y be possible fer 50 n ~
Site " to del iver "u r a o n t." 1I1(1_i1 ",0 users in r e a Lr t i.ne (e.;:!;., nr a n t, 1'l d J. l
a. t u 2 e r c 0:1 s o l e if us c r is cur r e n t, 1 Y 1 0 t: .; e d - in). T h email S.f .5 t e ,n <>. 1 S J
does not pr o v i ce a r,c neral Ln t.e r nr oc e s s c c mnu na c a t.Lo n facility, t. n c ur n
e

it ma y be p0 5si blp to d e l i v e r ne s s ~ g e s ~c pro ~ra ~s whicn h ~ve sailc cx

addres5~s. I nter-proce ss and int,er-ent it,y co ~nunication fac1.li~ies ~ re
Very desirable but are beyond the scope Of ~he network mail syste~.

The concepts oi " na a t box " and "na a Lo ox addresses" are central tv
this aiscu5 s i cn of n e twork mail system. A ma1ltox ia a plac e Where t he
the li1a i l i~ s t or ed be f o r c a u s e r c i.cx s it u p , It :i"lay be a fil~ a n t"i 2
user's direc tory or it r.~y be a bi~ for ha.rd-copy. The RailboX
address is t h~ a t d r e s s r eq uired b y the s e~der in order to s en d t he 1 1 ~ i l
to i ts des 1" Lna 1" i on n =1.11 o 0:' • For u se r s ".. . h 0 h a ve a n II 0 n -1 i:1 e II n e t, ',.10 r ~-:
mailboX, t ile ~2 i l b o x ~ j d re s s co~~ ains ~h e HOSt, ~ddress ar.d the user' s
li1ail bo>: i. d e nt. i£ ic~ ti cn C'. " t.h a t ;.jo s t . The I':", ailhox i d e n t i f i e a. tiol1 1. 5
th a~ whicn i s requireu by an FTP-server in order t hat. it m ~Y pu~ t h ~
mai l in t.n e c c s a r e c n a.a Lbo x , The ter ms n a a i.cox a d dress a nd a c o r e s s
will be used to reier ~o the on-line ne t-hork ~a11Dcx aadress.

NET ~()~K MAIL SYSTEM FU~C 'i"IOIIS

 The network ~ail system should provide the ,follo~in~

six functions:

, CREATING: This refers to the manner in" which the user crea~es or

omposes his me ss a ge . The F!P servers dO no~ explici~lY Drovide any

~ e s s a g e eaiting c a pabili~Y (server's eaiting conventions n a y be

applicable in t he case of MAI L co r : ~and). Editing conventions ~ucn
as ~nose for ch a~ac ter delete and line cancel vary wiaely over ~ ne
network. The user is m o s ~ familiar wi~h his local HOs~ conventlo~S
and these should he usee for ne~~ork ma i l eal~in~. lne user al~o n ~5
access ~o local ~ a i ~ i ng sys~e ns ¥hic~ can be used for conposin~ rn e ssa ~ e
files. The m e 5s ~g e file n a y ~hen Cp transmitted via the MAIL or M L ~ ~
com~~nds (: ILFL bein ~ ~re fer able). Th e presen~ fTP approach of ass u ~~n~
the creation of ~e s sag e s to be se~ rler'5 respcnslbility see ms ade qu~~ e.
TIP Users if they d e~lre e1itin~ f ~cilities s ho ul d use interrneolate
Hosts for creating and sen di ng mes.:ia ges.

2. LOCATI~G: Ho~ sen1er deter mines receiver& address. FTP a3su ~es

that t he s e n de r knc'.-l:; vr,e receivers correct ~:.d ci r e s s . There i s n c

pu oL'i s ne d or "on"lir.!~'1 list o f ;;J.;ilbcx ::..ddre~;sC3. There is, h o we ve r ,

a list of rie t.vc r k p a r t.a c Lp a n t.s :r.r-.intain cd (on-line) a n d c ub Ld s ne r o;y

the Net~cr k Ini of 8 ation Cen~er (~IC) at SRI- ARC. The net~orK u s~rs

. h a v e bee n a s s i F ned a 1.1 ~ i que " !~ I C I :j e n t " and fi o s t 5 i t, e bY the N1G•

It was therefore s peci fie d in FT? tha~ FTF-s Cl'vers maint ain a t~ ole
that ma ps NI C t o e nt.s t.o !":1 a i l - box a o e n t.a r a c a t.a on s , The NI C w~ll fl:";'J..tit. a.lJl
on -1 ine a nc pu b1 ish ~ he loca.l illedl c ox a j d r e s s a nr o r n a tion for n e t ',; 0 :' r\
partici p ~n~ s. It ~ould be rossitl e for users t o lco k up a pUbli3 h e ~
1St , or Querry th ~ ~ iIC on-lin e to loc av e de stina~ion ad d re s se s .
he NIC wi l l al so p r e v i d e a n on-li ne f acil ity (3i mil~r to fTP) that c a n
be Use d bY p r o~ r am s ~or re~ri evi~ r. the ~ddre 3s infor~ a~ion. f il l S l~tte r
apprOaC !1 of t he ~ I C I 5 ~ a in tai n in~ ~d ~ re s s e s has several advant~ge~.
The User c an ot t ai ll a nU ~ber of a d dres~es for a group, and use ~~ es e
to ~r an s n it nail. The FIP s ervers need no~ ma i n t a i n NI C Ide~t T ~o le s ,
and the Nl ee a r: pr o 'J i d e a £:0 0 d f a c i 1 i t, y for 1 0 c at HI gad d res s e s fro ill
last nanes, NIC id ent s, or e v e n s~etchY info rma~ion. I~ may s~lll ~ ~
desirab le t na~ iTP se r ve r s a c c e p ~ ~ I C 1d~nts , last names, and 'o~h er
standard for~s as ~ a i l b o x ider.~ifiers.

3 • SEN DI ~; G: How me s S :! ~ e iss e n t tot h e des till a t ion 1'1 ail bOX. The

me s s a ge s K~ y be sent directl Y to t~e de s t i n a ~ i o n n a i l box (v1a T £L ~i T

or Data co nnectio n s) ur via a n in~ er nedi~te ilost such a s t he ~ lC .

rTP does not eX ~l icl ~lY p r o vid e for ~ a i l forwardin 2 by int er ned l a t e

Hosts bu t FTP servers Ma Y be aDle to reco gnize a d d r e s s e s as not De1 n ~

local, an d f o r~a r d ~~ll. In tne e vent mai l lS to be ior War~ea, a

desir~ble fa c il i ty is ~o h~v e ~he int er~ edia~e site return an

acknowle ~~ e n ~ (bY request) upon deliv erY of mail or if delivery ~ ~ ll s

Within a s ; e c i f i e 1 ti ne. Th e c urr ent FTP sp ecifications r eco~ ~e l l d

that FTP-servers accent multiple addr esses bUt ao not require tnis.

 4. STORING: Where mail is stored before reading and if information

is available for later reference or retrieval. 'Tne rTP does not

reauire that sender store ~ail or keep duplic~te copies. It ~3

toe receiver's r esponsibility to store the information for readi~g,

~ierence, or retrieval. The receiver need not store the mail

_s a data file but can dir~ctlY print it out on a user console or
line printer. FT? dces not spec~:Y th~ orocedures for stora~e n~~Glin~
by inter~ediate sites. If intermediate site is used for forwaraing
the ~ail then it shoul d b~ the r~sDonsibility of that site to store
mail until it is delivered to its final destination. If the ma~l
is ulldeliv~ra'8le then the in'terneciate site shoula return the
undelivered in!cr~~tion to the s ender. A si~ilar situation arises
When sending of r a i l is def erred bY the sending site (aestin~tion
host rn~y be d o ~n). The sending site toen acts as an intermediate
forWarder inso far as t~e user ~s concerned.

5. I~['CORD I ~G: S h au Id the ~<til be c 3. tala ~ u c d and rec ore e c for 1;:1,. t e r

r'e r e r c nc c a nd r-c t.r a ev a i , f T P c ur r e n t Ly (lOCS not provide an

explicit r.ech ~r.is~ iQr the receiv er to recort nail. If an

inter rn 0diate ~ i t e (the NrC) is used for n a11 distrioution then

a function of such a si~e could be to record ~a~l, ii io requested.

NIC is iae al fer rec~rding m~il, but other sj.~es may also ~ish

to record ~ail. If the M~il is recorded, tnen ~t is not necessary

to ~end the entire co ntents of the Mail. Insteaa only a citation

for the dacume~t can he s~nt and the rec~iver can retrieve tne

mail onlY if he wdnt~ to. This is particularlY useful for lar~e

~ocurnents s uc h as N~ G/~FC whicn are distriouted to d group. ~he

.....-'
itation n a y c on t.a in a ut.rio r , title, r e t.r Le v a L p a t.nna me, and
pern ~ps an abstract.

6. HEADING: HoW the ma i l is finallY presentee to and read bY the

user. YTP currently as sumes that ~ail re aoi n ~ is entirely toe

receivin g site's functior.. Howevc~, there a r c ' ways in ~hich the

Sen Q ere a n aid t nere c e i v e r in pro v i din r; i ;·1 p I' 0 V e d ma i.l rea din g

facilities. Fe r exa mple, tne receiVing syst e ~J if it ~nows a '

message to be ur~ent can aeliver it im AediatelY at a user conso~e.

Long ~ess a ~es ma Y be cut in separate files with notification in

usel"s regUlar ~ a i l . Altern~tcly, mail coul~ De a citation t n at t~e

readin~ pra ~r a ~ can retrieve upon user rcauest. Selcctive

handlin g of di f fe r e n t classes of mail is inportant for an improved

networ~ mail system.

MOD ELS FOP MAIL SYSTEM US~

The user of a mail ~ystel~ can use inter~ediate site for locatin~
addres ses, recording an1/cr dis~ricuti~g ~ a i l , and for creatin g
and rcadin ~ Mail. We therefore have the following mo d e l s for ~ail
sys't,Cj.1 use:

 1. The user connects directlY to the destination FTP server and SellQS

mail using ~heMAIL con o!and. Locql editing fun~tions 'a r e li~i~ed to

characte~ delete and line cancel (assu ming user is in line-a-t~me

mode) ~n d server conventions May also applY. The user only nee ds a

3er-T~L~ET p~o gr a~ ~t his site but needs to KnoW the destinat10n

~ddress. This nodel i3 speciallY applicable to TIP and other M1ni­

Host users who do not have a user-FTP or user-Mail programs.

2. !he user cor poses the ~ail using a local cditor (o~ ~ail syste~~
and then reque3ts his user-rTP or ~ail progra~ to send the ~ail
directly to the dC3tin ation via th~ YTP MAIL or MLFL co m~ands. I ~ e user
needS to ~now t he destin ation addreRS. The mail can be deferrea b y the
send in~ pro gra m i f the aesti~ation Hcst is dewn. TIP users can U3e
this noo e i by us a n g tnt: facilities of a "hor,e-base" Host.

3. The user us~s 3n inter~ecti~te si~e such as NIC (other sites rn ~ y

pro v ide for ' /a r d i. n p: s . r vic e s t 00 ) for ;r. 2. i 1 d i [; t, rib u t, ion. l' h e u s e r

need not kn o w th e d e s t i n a t i o n addresses but can use NIC idellts for

indivi duals ana crou ps of in (!ividuals. The ~ a i l can be recorded o n

request a n a its sc~ci~ ~ can De d eferred (the oestina~10n Host wa y

be ao~n. or it rn ~ y t~ ~ore eco~onic a l ~o defer ~a1l). Tne m e sS a ~ e LO

be mailed nay ce cre at ed at ~ h e loc al si~E u sing local editing

facilities. or it may be created directlY at the inter~edia~e

site.

~. The User may s en G a citation of the rn~il instead Of the co~p~ete

ail ite~. Tne ci~ ation r efers ~o ~ n exi~ tin~ accumcnt ~hich
c a n be retrieved o n- line (s 'ucn a s the NIC nuroe r of Go NIC jour:1 al
cOliimunic ation).

HAILItlG TO TIP U SE R~
!'he TIP do es n o t, currently o r o v Lde an FTP server or ma.ilbox

faciliti es. while ~t is possibl~ to s end mail to TI? ter minals

(such ~s line ~rint ~rs) it 3e CMS un d ~ sir~bie to do so because Of

the possibility of Jc s in~ ~ a. i l , the lacK of privacy, and the

fact th~t USer May t:e ~ev er ~l (or sev eral hundre d) lii1 1 e s away

fro~ th e l ocation c: t ~e TI P. The TIP users nor ~~ll~ have a

"n cne oa s e " c on.pu t.e r '.Jnere they do their cCi7iputi:1 s; vor x mo s t of

the ti ne. The TIP lS er p r Obl em is ~ e 5 t solved oy requiring

t h a tTl P u .:> r s r e n t il P. i 1 o 0:-: e s a. t, the i r II h 0 j,'; e - bas e II H0 st. S uc h

a Host can prov i d e ~o c d n d1l rea di n g a n d Que rry f aci lities. A

TIP us ~r ca:; r e q u p. st h ~s "ho ;;: e" Host to Send h':" i:l nctif ic ation

of M a. i 1 0 naT I? t e r ~ i n a 1 • I f it 1 :-1 L co rm a n o 0 i'.' GI II FC !J. ;; 5 )

is accept ed in YTP, I I? uscr~ cuu l d u s e such a co m ~a ~ Q. More

importan t, if the us~r has a nU ~b er cf ~i 2 i l c o x e s on aifi er en~

Hosts, the RD XL (or ~G M ?) c c~~and ca n be usp.d to rea d his mail

at all the sites where he has mailbo xes.

 ACC ESS CU ~ T ROL I N MA I L SYSTEM

I~ ha s be en s~ ~ ~ e3t ec t ~a~ FTF specificat ion s~ould require

that n a a L r u nc t i c n ( r c r r e c e a v d n z n a i l ) should oe "f r e e" , i.e.,

TP s e rv e r s sh oU:' d n a t re quir e t he u ser ~C "lof.in" · ( s e nc t.n e U S ~ p., ~'A S ::> ,
nd Ace T c c mna n a s ) , In t he a o s e nc e of the access contro l c on n a no s
the FTP 3erver s ho ul d c har ge t he c~st of receiving ~ a 1 1 to an

o ve r h e a d 0 r b r c ~~ 5 i n ~ a. c c 0 un t, • It s n 0 u 1 tj t: e not edt h a t t ~1 i s " ire E: II

mail f unc t ion us i " g c e f a Ul t II US E ~

II a c count, r'lay not allo;.; non

mail-rel a t ed c O ~ w ~ n Js wi th o u t reinitia11zing. ~ h i s require~eI1t ~i l ~

inprove co ; n un i c a t.a o n 2.1":". 0 1, '" the net . . . o r x users.

SO Me sys~e m s, s Uch a s M U 1 ~ 1 C S , nave meCnan1s~s ~or access

control in t he r ec ei ct of ~ a.i l . T~at i s a User can specifY· who

is eli ~ible to s e n j ni m ma i l (nor n all Y users ~ i v e . ~ h e acc ess

"*.*.* ". i . e •• a nv erie ca r, se ne r; a i l ) . The acc e ss central

c 0 !l';f 1 ;:W '; 5 ;.;0 U 1 d b n r <>: 1 u i r ~ d to ;:; a i n p r i 'I i 1 e 2, e ~ a c c e s S • T 11 e USE H

C orui a n« o o c s n c t, s e e r: t.n e C ~ [- t, ..... a y 't o i rj e n ~ii:{ t he s e n c e r of

mail. c o ns i der us er 3 lO f ge d in as GUi tiT, IeeC, N ~ T W O R ~ , MI T -D~ CG ,

an d UET ~O~ K -USE H . A s e p~r ~t e ¥ ? OM co ~ n a ~d se ~ m s desir ab le. Suc n

a omna n d c a n b e us e d t.o i d cn~ l fY ~ he s e n Ge r a s we l l as to send

. a c k n o ~ i e d ~ n e l l t s a n a r e pl i e s . Tne rec eiv in g si t e can ~a ~ t he ~ a 1 1

as: F ~ OX A ~ B at HI T -G ~CG , l o ~ ~ e~ i~ as GU~ST. Tne r ec eiv er c~~

then send re pl Y ~o t he Hail bo x ad dres s A~ B at Host 10 (S N n ~S G

AKB~D MCG or MAI L D ~C~ AKrl).

NETio/O RK I I: fO f.~ :1ATIO I ; C i:.~T£ R FUHC TI O:1S

The Nl C 1 13 a ve ry spe ci a l f (l c i l i~ Y f o r h Cl n ctlin r; rna.il. It

rovid es fa c i l it i e ~ fo r r eccr a in ~ a n a di stri ~ u tin g m3 1 1 to

--~ n n i v i d u a l s ~na ~ r o u n s of in d i vi ctu a l s, 2~d ior loc a~i n ~ u se r s '

add r e s s e s • '£h e ~iI C :.; i 11 a 1 sou n a e r t. a !< e to Dr 0 v ide d 1 S t r a but ion
of unr eco r de d r ai l. Cur r'cn~ lY the ~IC r eouir e s t hat u s e rs l og
into t he Nr C a ~ 1 u s e ~ L S t o cr e a t e a nd d i s~ri but e m a11.U s in g
NLS for cr' e ati n ~ ~ ai l has oee n a iru s t r' a tin ~ e x pe r i e n c e f o r' many
Who a r e us e d t o d i ~ f c r' cnt e ~ : t i n ~ ~y s ~e m s. ~e c e n t l y th ere na3
been a pro bl em t hat ~ I C is ov ~rload ed at ~ o s t t i ~ es of t he d ay
a n d ev en i f one c an ~ e t a " n c t ~ or k ~ er min al" a nd lo~ in, t he
interact io n is q u i t,e Sl OH . AS iH C ( o r liLS) ~-s c e s a gn e o f o r
char ac t e r- a t - a-~~ ~ e i n ~ e r a c t i o n ~ i tn r c r.ote e c hO, t he us e is
in effici e n t. v s in~ ~ l C i s p ~ r~icular lY unbe~ r a o le ~ h e n the user
fall S be hi nd i n ;li oS e c n 0 bY as n u c n as a.n e nt.a r e l~n e.

An alt ern ative to di r ect us e of NI C is to us e the NIC via FTP

and pro g r a ~ s at t he u ser' s si te . The use r can cr e at e journ al
doc u ~ e n~ s u 5in ~ his o wn l o c~ l ed i t 1 ng sy s ~e m an d t hen tr an s f er
it to NIC vi a FTP. 7 ne us e r may h ~ ve to s peci f y 6 u c h i n ;o r~a t l on
as auth Or' , t it l e, ~ h er e ~ ll e a c~ n o ~le ti g~ e n t s ho uld b e se nt , a n a J o u r n ~ l
nunb er i f t h e i t e ~ i s to oe re c or' d ed . It s hOUl d als o be pos s1b l e
for User s to s end s equen~i al f i l e s t o NI C an d h ave the m r estruc ~ r e ~
Ln t o NI. S f Cl":"l '..; i t- hout n a v t n z t.o d o a n "i n put s eq ue nti a l II (a s u c ge s v.ic r:
is t.o II NL S II t h e fi l e if it s n a me a s suf fixed 'fi i ~ 11 a • NL3 ) . Al t e r n a \'clY
 it should be possible for user's to retrieve journal aocuments ana

other sequenti~l files without having to do a previous "output

sequential" •

The NIC curentlY delivers ~ail via hardCopy and/or on-line.

On-lin e currentlY ~ e a n s tn at u3er ~ u s t log i~to NIC to see if he
has a lll C S S 2. ?- C an d r e a c it by "print o r anc nv , 'l'he ne s s a ge s are not s e e n
by the destination users for several days and Many users ~et t~e~r
hara copy before t hey have h~d a chance to exaMine their on-line Nl C
mail. If the NI C were to d e l i v e r ma i l via FTP to net wor K users, tncn
the nail t urn- aro und t im e will be ~ rea t l Y speeded ana the users ~i l~
not hav e to lo~ i n t o t~e NI C. Large dOCU Ments need not cc m a ~ l c c
to the U3 e~ in t heir e n t i r ~ t y but onl y a cit ation need be sent.
The NIe wil l n av e tc c o ll ect t he i n for~ation on the ~a i lb o x addre 3~e5
Of Net~or k pa r t i c i ~d n ts ~or d e l ~ ve r i n~ ~ a i l , e s ~eci~lly "since it
a p pea r ~ t, h 2. t r:: anY:"T ? s e r v e r s a r e not "r e s p ~ c tin 2: " ;Ij I C l oe n t s •
I t i s !' e c 0 ~ n i 7. e d "t., hat a USe r ma Y :1 a v e P1 0 ret i1 J. non e va ll.Ci na i l boy,
address, but t~e NIC needs to riave only one (tne most used) of t nese
addresses.
The NIC ident ifica~ioIi sUb5YStc~ (currently accessable via ~LS
on 1 Y ) con t, a ins i n i 0 l' :n a t, ion 0 nus ~ r S ( s uc has a. iii 1 i a t, ion, U S ~1 all
address. t el e phone n u n oers, etc.) a nd ~roups ( me n bers, etc.1. Tne
on-line nailboX ad j1' c35 ~niorGation can be addea here. The NI C
will un d er~ake to p ro vi d e a !a c i l i t y wnerebY the identific atio n
subsyst e M can te Gu erriea by pro ~ra ns, allow 1n g nailin ~ prn ~ra m3 to
retrieve the addres s es autonaticallY. This facility will be s e p ~r~L~
froj;1 FTF.

-r TP 110 !) I FI e AT I Ni S
The rTP c~rrcnt.lY dces not provi de explicit facilit iies for

recordin ~ ~a i l . c o ~ n u ~icatini ~end er13 a a~r ~ s 3, se ndin~ pro Jra ~

readable for Q o c u ~e n ~ s ,

c ita'tic~s, s~eciiYi n ~ ~utn or a n d t~ t. lc

requestin g ack~o~l e d~ ments. an d in dicatin~ ~ e s sa g e type (ur Gent,

ordinary, a nd lo n ~) . To o verco me th ese def ~c iencies, we" can ta ke

any of the folJ.o ;·;i ng a p p r o a c nc s t

1. KlUdge the desirect features in the p a t h n~ n e sYntax of the MALL

and MLfL co~ ~a nd ~, Just i f yin g t he ~lu dge on the gr o un d s that

no s t. of the i unc',ions are to be Used on Ly by the NI C.

2. Add new co ~nand3 for the desired f unctions and al t e r the

MAIL and h LFL c o m~ands sone~hat to reco ~nize the existence

of the ne~ cc ~ nands.

3. ~efine a ne~ Mail co~ mand Whic~ incorpor~tes th_ " ~issin~

functions (in t h e proc e ss defirlin~ n ew co~ ~ands for the uesir e d

functi ons). The ~AIL and MLFL co ~ rnands can be u~ e d In their

 present form but May be ~raduallY phased out.

The first aporoach see~s unde~irable to me as many of the

clissing functions can ce used bY other sites as well. In addition
it will be easier ~o ~rite programs to d eal With cc n ~ an~s r~tner
th~n a cor,plex sYntax. The second and the third approaches
are not very 6ifierent fro~ eaci1 o~her. The third a~ proach seems
prefer~ble as it will allow existing mail procra~s to function in
their prese~t form. using the third approach consider the follo~in~
new FT? co~ ~~nds:

1. MLTO (nail to): The argu~ent is one or more mailbOX identifiers

s epa ~. ate d ~ Y I I , II ( c 0 f" "~ a s l , I t i s s up; £; est edt 11 a t, i:f the r e 1. :> no

ar~uncnt, t h e na J.l should be sent to 9 0 ~ e responsicle user or

c r f.nt.co on ;:1. pri n t er. rhis c oran a n o s t.a r t.s tile se c u e n c e of op\,-io.1<!.1
FTP mail related co ~ m ands aescribed below. The sequence ends
with the TEXT, FIL E, or ClTA (citation) comnan6s.

2. :nW :1: The a r g une n t is the a do r e s s of the sender or senders. It

is in a stanjard for~ tllat can be interpreted by pro~ra~s as weil
a s huna n u s e r s , Th e a n r o r n a t.a o» is to lie used for idcntii'y:i.lI g
the sender(s), for sendin~ replies, ~nd for senain~ ackno~leag~en~s
if the receiver is an inter~ejia~e fO~'warding si~e.

....- . MTYP (mail tY~ 2): This identifies the type of mail as U (ur~en~'J
() (ordin a.ry), ;;.n d L (lonr.). The r e c e a va nx s y s t.e n can t.a ke t ne
a pp r-ocr-d a t.e a c t.i.on s f r o n t.n i.s knowled ge. The ctefd.ul t as s um c t.a ou
is ordin ary m ~ i l .

h. RECD (record the ma i l ) : The ar~ument if present is the iden~ifyill ~

infor mation for reccrcin g (such as Nr C Journal nun oer). If no
a r gumen t i s pr-e S Ui t the serve r i'l ill a. 5 si c n th e r-ec cr o i.n g infor-:l a t.Lo n
and send an appropriate r~plY (real-time or aeferr ea).

5. AUT H (a u tho r): I d e n t i fie 3 t ~1 e rl.u t n 0 r 0 r t ned 0 c un e n ~ ina. for ill

a.cc e o t.a ble to the server (N I C ic.1ent iilay t.e r e qua.r e c by NIe) •

6. 'l'ITL (title): lae~tifies the title of the ooc une n t. , 'i!1e a r gune n t..
is an ASCII strin g e nc i ng with the sequence "CHLF. ·RLf " .

7. ACK~ (ackno~ledge): Relev ~nt for inter mediate for ~ arding sites.

ASKS the server to send ac~nowledrrr:ent on deliver y or if delivery

tails within a speci fieu tiRe.

........ ..
~
7

8. T~XT: NO ar~u~ents. starts the transfer of mail over TELN~T

connec~ion in an ident~cal ~anner as ~AIL •

• FILE: NO ~r~uMents. Starts transfer of mail over the data cOllnectic~

in an identical Manner as MLFL.

10. CITA (citation): Ar~unent is the path name of a retrievable file.

We alsO ne ed to define new renly codes for nandling nail. ~O i~e

sites have ex pressed the nee d fer reolie s suen as "send onlY X oyt e s
Of nail". Ot her r e p l i ~ s could soe e i f i c a l l Y req uest ~ t a i t i e n ~ l cc~ m~D C S
such as U5 ~ ~/ ? ASS/ A~C T f or nriv~li ~ed n a il i n~ , f RO~/ ACAN fer ~~il
for~ardin gJ an ~ A T ii / T 1 T L for reco r ded m~i l . Ano~ her su~g es~lcn tn ~~
~aY be ~ i v~ n consi deration i s a l l o~ i ~~ TY?E/dYT E ot l\er than AId f or
FILE co ~n J~ d. Maili~ ~ l arpe fi l es be~ ~e en l ~~e mach ines s ucn
as PDP-lOs i s n o r e ef f i c i en t in 1/ 36. The RDML ana RD ~ i co ~ ma~~~
proposea b y Br e s s l e r and T~o ~as (~ ft G/2FC h58) ~ l s o m e r ~ t c onsld~ratl o n
as theY would aid t he handlin R of mail for u sers Who have ~ a i lb o x e 5
at different Hosts.