[SATLUG] Slow Email Sending
brad at shub-internet.org
Sun Nov 4 00:32:39 CDT 2007
On 11/3/07, Samuel Leon wrote:
> Ok I got a funny question. Why do some emails get sent really slow?
What's in your logs? Have you put up WireShark to watch all port 25
activity, so that you can see in real-time what the mail servers at
the other end are doing in response to your delivery attempts.
> I run my own email server. Sending emails locally is instant. I just
> right now made a new account and it was working fine locally. I tested
> it remotely by sending an email to it from myway.com, gmail, and juno.
Therein lies your problem. Many home e-mail servers are run on IP
addresses which are designated as "dynamically assigned", and most
mail servers on the Internet are configured to reject connections
from any IP address that is listed as "dynamically assigned".
Instead, try passing these mail messages on to the MTA operated by your ISP.
> I waited and waited. 10 minutes passed and still nothing. I finally
> tried sending it an email from a remote email server that a friend runs
> (it relays off of a grande communications server). I checked the logs
> on his side and everything looks fine:
> to=<xxx at xxx.xxx>, relay=mail.grandecom.net[18.104.22.168]:25,
> delay=0.79, delays=0.17/0.02/0.16/0.43, dsn=2.0.0, status=sent
> (250 2.0.0 lA47ktr03001 Message accepted for delivery)
> Yet here it is an hour later and I still have nothing.
This tells you nothing. Two of the three domains you mention above
are high-traffic sites, and there's a good chance that their mail
servers are too busy to accept mail more often than not, especially
during "peak" hours (usually something like 6pm-midnight during the
week, in the Eastern timezone).
Unless you're sending a statistically large number of messages to a
statistically large number of recipient sites, and you have accounts
on both sides of the house so that you can track when you send the
messages and when those messages arrived, you can't tell anything
useful about the systems in between those two points.
> Lucky some of
> the other emails I sent from the other servers are starting to trickle in.
> I don't think this problem is on my side.
You have no evidence for this. Moreover, I doubt you have enough
evidence to prove anything, but at the very least we need to get a
lot more detail about what you've got in your logs and then we need
to be able to compare those against other sites and what they're
seeing in their logs, for the same time period.
> I have never seen delays like
> this though. Is this just typical of enterprise level servers? Some kind
> of queue where the messages wait in line for hours waiting to be
Dunno. What's typical at one site may not be typical at others.
OTOH, there are some common practices which are widely shared. Which
side of that divide you fall on is difficult to determine without
> Also I see in the log clip above "delays=" and "delay=". Is that some kind
> of local statistic or what? I can't find anything on google.
You'd need to know what kind of mail server they're running in order
for those lines to make any sense.
Brad Knowles <brad at shub-internet.org>
LinkedIn Profile: <http://tinyurl.com/y8kpxu>
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