How are Your SMTP Timeouts Configured?

Asprin asks: "One of the employees at work had a major headache because a very important email was undeliverable for more than 24 hours. Sure, he got an warning from our server about it, but only after an entire day had passed, and the email was no longer timely. Therefore, I shorted the message handling timeouts to send 'delivery delayed' warnings after 30 minutes and to cancel the message as undeliverable after four hours. Now, I don't expect any of the other mail administrators here to bless these timeouts because they're way too short. HOWEVER, the truth is that my users rely on email to be as reliable as telephone messages, and if it can't be delivered immediately, it is better to reject it outright and alert the user so that other communication channels can be exploited such as fax or Fed-Ex. Is anyone else doing this? Are there any non-obvious ramifications lurking? Pros? Cons? Comments? Should we all reduce these timeouts on our SMTP servers?"

Comments

Up here in the great white north

[the_other_one]

We use dogsleds.
If the dogs come back wanting food without the sled.
Then the driver was eaten by a bear and the
message did not get through and the sled
sunk below the ice.
Resend Message
else If The dogs come back with the sled but
without the driver and w/o reply
Then the driver was eaten by a bear and the
the dogs were hungry so they came home.
Resend Message
else If The dogs come back with the sled and
the reply but without the driver.
Then the team made it to the destination
got the reply but the driver was eaten
by a bear on the way home. However,
the dogs were hungry so they returned.
else If the driver returns with the team and
the reply.
Then the reply is a fake. The driver hung out
at the brothel down the road for a few
weeks and faked the reply.
Resend message.

Education is the answer.

[natmsincome.com]

After the Sobig virus so of our email were taking 3 hours to get through and alot of our users were asking us why it took so long to send an email to someone that was less than 20 meters away (our ISP still does our email as I haven't had time to set one up in house). After getting close to 20 people asking me the same question I sent out an email giving everyone a quick idea of what happens under the hood and how it was a miricle that they got email at all.

It went something like this (short version):
When you click on send the message is sent to our ISP. Our ISP then sends it to another ISP (our old ISP that till host our mail)which then sends it back to us. At each ISP it goes into a que with 1,000 of other messages. For your email to get from you to the person 20 meters from you it has to travel 6000+ km (Australia is a big country and our current ISP is in perth) and it normally does this in less than 5 minutes.

Also there are currently two viruses on the internet that have slowed down the entire internet: SoBig and Slammer.

After I sent the email out and explained how email worked and why everything was so slow lots of the users told me that they never new so much happened in the background. I haven't had anyone complain about email again.