Mail RFCs, Längenbeschränkungen

[Tom]

Hello,

Eine einzelne phsyische Zeile in einer standardkonformen E-Mail kann also nie länger als 998 Zeichen+CRLF sein. Ein einzelner Header kann durch Folding und Unfolding aber durchaus wesentlich länger als 1000 Zeichen sein.

Das verstehe ich anders. Steht auch an einer anderen Stelle nochmal anders. Muss ich aber selber suchen:

Eine einzelne Zeile kann maximal 998+CRLF werden.
Bei Überschreitung der 78 Zeichen (für die Lesbarkeit, Convenience) kann gefaltet werden.

Das ist noch von Jonathan und mMn noch gültig, weil in RFC 822 und RFC 1341 nochmals kompatibel wiederholt. Das habe ich aber nur noch so im Gedächtnis und noch nicht wieder neu rausgesucht:

4.5.3.  SIZES

There are several objects that have required minimum maximum
         sizes.  That is, every implementation must be able to receive
         objects of at least these sizes, but must not send objects
         larger than these sizes.

****************************************************
          *                                                  *
          *  TO THE MAXIMUM EXTENT POSSIBLE, IMPLEMENTATION  *
          *  TECHNIQUES WHICH IMPOSE NO LIMITS ON THE LENGTH *
          *  OF THESE OBJECTS SHOULD BE USED.                *
          *                                                  *
          ****************************************************

user

The maximum total length of a user name is 64 characters.

domain

The maximum total length of a domain name or number is 64
               characters.

path

The maximum total length of a reverse-path or
               forward-path is 256 characters (including the punctuation
               and element separators).

command line

The maximum total length of a command line including the
               command word and the <CRLF> is 512 characters.

reply line

The maximum total length of a reply line including the
               reply code and the <CRLF> is 512 characters.

[Page 42]                                                         Postel

RFC 821                                                      August 1982
                                           Simple Mail Transfer Protocol

text line

The maximum total length of a text line including the
               <CRLF> is 1000 characters (but not counting the leading
               dot duplicated for transparency).

recipients buffer

The maximum total number of recipients that must be
               buffered is 100 recipients.

****************************************************
          *                                                  *
          *  TO THE MAXIMUM EXTENT POSSIBLE, IMPLEMENTATION  *
          *  TECHNIQUES WHICH IMPOSE NO LIMITS ON THE LENGTH *
          *  OF THESE OBJECTS SHOULD BE USED.                *
          *                                                  *
          ****************************************************

Errors due to exceeding these limits may be reported by using
         the reply codes, for example:

500 Line too long.

501 Path too long

552 Too many recipients.

552 Too much mail data.

Liebe Grüße aus dem schönen Oberharz

Tom vom Berg