 4.     SMTP, . 14_______________193

          , . .
    TRANSACTION.  - 
"-ERR",      ,    
 :

: USER mrose

S: +OK mrose is a real hoopy frood

C: PASS secret

S: -ERR maildrop already locked



: USER mrose

S: +OK mrose is a real hoopy frood

C: PASS secret

S: +OK mrose's maildrop has 2 messages (320 octets)

        -
   -.    -
  (    USER  PASS)  -
                 
AUTHORIZATION    ,    -
      
 .      
-      
   USER/PASS.

 name digest

  : name    ( ,   
 USER), digest   (  MD5)  .
      
       . -
        . -
,  UNIX-     : <process-
ID.clock@hostname>,  process-ID    , clock 
     , hostname  
 -.      
 .      .

S: +OK  server ready <1896.697170952@dbc.mtview.ca.us>
:  mrose c4c9334bac560ecc979e58001b3e22fb
S: +OK maildrop has 1 message (369 octets)

     "tanstaaf   
<1896.697170952@dbc.mtview.ca.us>         
"c4c9334bac560ecc979e58001b3e22fb".