Re: [Sheflug] sendmail & cannons

["Chris J" <xxxxx [at] xxxxxxxxxxxx>]

> Can someone explain the action of the sendmail FEATURE('nocanonify')?

Huh - a dull question like that? I thought we were about to discuss the 
control of big guns via email notifications :)

Anyhow ... IIRC, canonifaction of an address essentially means verifying 
and/or expanding a domain name, so it plonks a domain on the end if it 
doesn't have one.
> 
> Sendmail has been getting slow - lots of email and only a 56K dialup.
> Looking at some sendmail tuning information I added FEATURE(nocanonify) to
> my m4 sendmail config source and it is now a lot faster. (Fast enough to
> now run with background delivery rather than queue-only)

Yep - sendmail will no longer attempt to do any DNS lookups (apparently just 
saying nodns doesn't solve everything).

> 
> I know this reduces DNS activity but what exactly does it do and what have
> I lost by disabling it?
> 

Things lost ... some searching has found this on Google Groups:

	"If you don't canonify, then no MX lookup will be done for 
	LOCAL_RELAY or SMART_HOST."

There might be more on what it does and what goes missing, but every search I 
type for "canonify" and "canonification" pulls back something that says "if 
you switch it on/off you'll achieve foo", and the term only seems to be used 
within sendmail, with the odd mention of the term in a BIND newsgroup. So I 
think it's a term that's falling out of favour outside sendmail :)

m4 macros, sendmail.cf and the shear bloat of sendmail (with the ability to 
tweak whether messages from domain foo need to be directed via UUCP down the 
piece of wet string to a waiting bucket) was one of the big reasons I left it 
(other being security).

qmail and postfix are a little leaner and a tad easier to configure :) qmail 
requires DNS somewhere however, postfix doesn't need it.

Anyhow, someone who knows sendmail better might be able to give a better 
answer than this :)

Chris...

-- 
\ Chris Johnson           \ NP: Linkin Park - 12. Pushing Me Away
 \ cej [at] nightwolf.org.uk    ~-----,   
  \ http://cej.nightwolf.org.uk/  ~-----------------------------------, 
   \ Redclaw chat - http://redclaw.org.uk - telnet redclaw.org.uk 2000 \____


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