Email Alerting with DRAC5
Brian A. Seklecki
lavalamp at spiritual-machines.org
Wed Feb 4 11:30:40 CST 2009
here's tehe thing -- RFC2821 says:
" ...consolidates, updates and clarifies, but doesn't add new or change
existing functionality of the following:
- the original SMTP (Simple Mail Transfer Protocol) specification of
RFC 821 ..."
But it also says:
"It obsoletes RFC 821..."
Here are my notes from July of 2008:
Page 30 of rfc821.txt actually indicates that "[188.8.131.52]" is a
valid SMTP FROM syntax:
MAIL <SP> FROM:<reverse-path> <CRLF>
<reverse-path> ::= <path>
<path> ::= "<" [ <a-d-l> ":" ] <mailbox> ">"
<mailbox> ::= <local-part> "@" <domain>
<domain> ::= <element> | <element> "." <domain>
<element> ::= <name> | "#" <number> | "[" <dotnum> "]"
Where [DotNum] is okay.
"Sometimes a host is not known to the translation function and
communication is blocked. To bypass this barrier two numeric
forms are also allowed for host "names". One form is a decimal
integer prefixed by a pound sign, "#", which indicates the
number is the address of the host. Another form is four small
decimal integers separated by dots and enclosed by brackets,
e.g., "[184.108.40.206]", which indicates a 32-bit ARPA Internet
Address in four 8-bit fields."
On Wed, 4 Feb 2009, Brian A. Seklecki wrote:
> > 3.6 Domains
> > Only resolvable, fully-qualified, domain names (FQDNs) are permitted
> > when domain names are used in SMTP. In other words, names that can
> > be resolved to MX RRs or A RRs (as discussed in section 5) are
> IIRC, our determination that IP addresses were acceptable was from RFC822,
> maybe not. It has been a while:
> 4.1.2 Command Argument Syntax
> MAIL FROM:<reverse-path> [SP <mail-parameters> ] <CRLF>
> "MAIL FROM:" ("<>" / Reverse-Path)
> [SP Mail-parameters] CRLF
> >> If I recall correctly, reverse-path had some object dependencies that
> >> let both a string value, and dotted decimal value be valid
> 4.1.3 Address Literals
> Sometimes a host is not known to the domain name system and
> communication (and, in particular, communication to report and repair
> the error) is blocked. To bypass this barrier a special literal form
> of the address is allowed as an alternative to a domain name. For
> IPv4 addresses, this form uses four small decimal integers separated
> by dots and enclosed by brackets such as [220.127.116.11], which
> indicates an (IPv4) Internet Address in sequence-of-octets form. For
> IPv6 and other forms of addressing that might eventually be
> standardized, the form consists of a standardized "tag" that
> identifies the address syntax, a colon, and the address itself, in a
> format specified as part of the IPv6 standards .
> And this section:
> 18.104.22.168 Extended HELLO (EHLO) or HELLO (HELO)
> These commands are used to identify the SMTP client to the SMTP
> server. The argument field contains the fully-qualified domain name
> of the SMTP client if one is available. In situations in which the
> SMTP client system does not have a meaningful domain name (e.g., when
> its address is dynamically allocated and no reverse mapping record is
> available), the client SHOULD send an address literal (see section
> 4.1.3), optionally followed by information that will help to identify
> the client system.
> > permitted, as are CNAME RRs whose targets can be resolved, in turn,
> > to MX or A RRs. Local nicknames or unqualified names MUST NOT be
> > used. There are two exceptions to the rule requiring FQDNs:
> > - The domain name given in the EHLO command MUST BE either a primary
-lava (Brian A. Seklecki - Pittsburgh, PA, USA)
"Show me a young conservative and I'll show you someone with no heart.
Show me an old liberal and I'll show you someone with no brains."
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