Shorten delay in sending mail to SMTP

[Foo JH]

Olivier,

I have no visibility on the delay on which external smtp servers deliver 
mails to my mail server. Once a mail is sent out of my mail client, the 
mail can be received immediately through my imap client.

To give a more detailed picture on load, my Qmail does not really a 
heavy load. I'd say at 9 times out of 10 there are no mails in the 
queue. Everything is stored locally so I have no reason to suspect 
internal network delays and all.

My suspicion with the delay being related to dns lookups, is partially 
also because I wait a couple of seconds less when I am sending from 
within the same service provider. Yet when I (for example go home and) 
send from another service provider, the delay is longer (by a couple 
more seconds). Do note that I am on all tests on broadband, so we can 
assume network delay is negligible.

Can anyone confirm that Qmail/ inetd/ FreeBSD does some form of dns 
lookup on it's SMTP?



> Do you receive email from outside world on this machine? Do you think
> there is the same delay?
>
> How do you notice the delay? After Thunderbird mentionned that the
> email was successfully sent, you immdiately try to get new email from
> your inbox and it takles time?
>
> How big is your inbox? What mailbox format are you using? Are the disk
> local or network mounted? How much loaded is your machine? How many
> emails do you receive at time? Do you read with pop or imap? Are
> pop/imap launched by inetd or they are daemonized? Do you have any
> anti virus/spam facility? Do you implement some fancy MDA like
> procmail?
>
> Remember that email is not instant messaging, but store and forward:
> it is a slow and batch processing, it is dessign to support delay and
> certainly the design should generate some.
>
> If the delay remains 5 seconds when your server process 1 or 10000
> messages per hour, then there is nothing to worry about.
>
> Authentication should effect only to sending, it deals with the
> communication between Thunderbird and qmail. It has nothing to do with
> reading your mailbox and should have nothing to do with the in between
> delay.
>
> Bests,
>
> olivier
>