mozna chyba v /usr/sbin/sendmail ???

[Lubos Kaspar]

> Date: Wed, 25 Sep 2002 23:02:08 +0200
> From: Dan Ohnesorg <Dan na feld.cvut.cz>
> To: sendmail na linux.cz
> Subject: Re: mozna chyba v /usr/sbin/sendmail ???
> 
> Dne Wed, Sep 25, 2002 at 07:43:29PM +0200, Marian Cavojsky napsal:
> 
> > Niekde som pocul (cital), ale nebolo to RFC, ze sa bodka na zaciatku
> > riadku (podla nejakeho RFC) ma zdvojovat.
> 
> Ano, ale to se dela pri prenosu pres SMTP mezi dvema servery a ne na
> lokalnim stroji.

To je mozna ponekud nejasna formulace, nebot pri SMTP-relaci je vzdy
pasivni strana serverem a aktivni klientem, takze "SMTP mezi dvema
servery" asi nedava dobry smysl. I na lokalnim stroji asi odesilatel
jako klient predava zpravu nejakemu serveru; odchylkou muze byt snad
jen pripad, kdy "primary submission" je formou ulozeni zpravy do fronty,
aby ji nasledne odeslal (SMTP-serveru predal) jiny program ve funkci
SMTP-klienta.

RFC 2821:

: 4.5.2 Transparency
: 
:    Without some provision for data transparency, the character sequence
:    "<CRLF>.<CRLF>" ends the mail text and cannot be sent by the user.
:    In general, users are not aware of such "forbidden" sequences.  To
:    allow all user composed text to be transmitted transparently, the
:    following procedures are used:
: 
:    -  Before sending a line of mail text, the SMTP client checks the
:       first character of the line.  If it is a period, one additional
:       period is inserted at the beginning of the line.
: 
:    -  When a line of mail text is received by the SMTP server, it checks
:       the line.  If the line is composed of a single period, it is
:       treated as the end of mail indicator.  If the first character is a
:       period and there are other characters on the line, the first
:       character is deleted.

Zdvojovani pocatecni tecky na datovych radcich tedy musi delat
SMTP-klient, jeji nasledne odnimani naopak SMTP-server.

Jak jiz psal p. Ohnesorg dale, problemem byvaji obvykle vselijake
bastly (at uz servery nebo klienty), kdy se jejich autori neobtezuji
precist si prislusne standardy. Taky jsem mel jeden takovy pripad.
--
Lubos Kaspar