Topic: Deferred outgoing email - is it possible?

[gbentley]

Hi, we have an SME on the LAN and a single ADSL serving 20 PC's - there is a lot of email and drawing attachments making up MB of email data traffic to our ISP mail relay that sometimes kills the connection for anything else (upload speeds are in order of .3 to .5 MB)

Is it possible to deferr outgoing / relayed email at all?

Was thinking if we did this once on the hour everyone would know to avoid those times for surfing?

[janet]

gbentley

qmail will utilise all available bandwidth if allowed, meaning it will send as many email messages as possible at the same time (concurrently). IIRC the default is 40

The simplest answer is to throttle the concurrent number of outgoing connections
eg
config setprop qmail ConcurrencyRemote 5
signal-event email-update

Adjust the number of connections to suit your requirements, you may need to experiment to find a happy compromise between speed of sending & receiving messages and web browsing speed etc.

check with
config show qmail

[CharlieBrady]

Hi, we have an SME on the LAN and a single ADSL serving 20 PC's - there is a lot of email and drawing attachments making up MB of email data traffic to our ISP mail relay that sometimes kills the connection for anything else (upload speeds are in order of .3 to .5 MB)

You can suggest to your users that they use one of the many sharing websites (dropbox, pastebin, google docs, whatever), and just post a link via email.

[Stefano]

or, if your SME is not in server and gateway mode, use a firewall to make some trafic shaping and sharing files via an ad hoc ibay (I usually do this way.. no need for additional sw on the clients, simple cut and paste files into /files dir and instructions to the monkeys...)

[gbentley]

Thanks all for suggestions

[janet]

gbentley

To actually control/limit/share the outgoing bandwidth, look at the wondershaper Howto which AFAIK works OK.
Otherwise try the wondershaper contrib, but I think the current contrib(s) are not working correctly, refer bugzilla & the Howto.

Please report back your outcome, I am interested if the suggestions resolve your issues.

[gbentley]

thanks janet - tbh I am only using the box for a local mail server [not proxy / gw etc] so at a brief look dont think this would help me. May look into the router config see how flexible it is.

[purvis]

Even tho your server is not in gateway mode, you can use the SME server for a web proxy for browsers on your workstations. This should cache some of your web activity. How effective. I do not know. The dns lookup should be cached as well and you will also benefit from the excellent networking efficiency that linux has built in too.

[janet]

gbentley

I am only using the box for a local mail server [not proxy / gw etc] so at a brief look dont think this would help me.

If the server is not the gateway then shaping will not help much on that server, you have to do that in the gateway/router

The qmail settings I advised
ie
config setprop qmail ConcurrencyRemote 5
signal-event email-update
will definitely slow down (or defer) the mail & the result is less bandwidth usage at any point in time, which is essentially what you requested, try it & see, it will only take 2 minutes to implement.
To return to standard settings do
config delprop qmail ConcurrencyRemote
signal-event email-update

which just allows the templates to use the default value (40) when there is no other value specified in the config database

[gbentley]

Thanks Janet - I did this as soon as I read your message - am not on site so need to get feedback from the office.

[Stefano]

I would say that sending BIG attachment with email is definitely a bad practice

email is not a file sharing protocol/tool

gbentley: I would publish an ibay with no php and sent email with simple link to the file

[gbentley]

Depends what you mean by big - drawings are typically 8-10MB but there are multiples and there are 20 odd staff doing this regular. So when the server is relaying, our poor .4 mb upstream is somewhat hampered.

This is also the case if staff use dropbox or upload via FTP to our webspace.

[CharlieBrady]

gbentley: I would publish an ibay with no php and sent email with simple link to the file

That won't necessarily help with the problem. That might mean that instead of sending 20copies of the file there would be 20 external users fetching the file. Still 20 file transfers taking place.

My suggestion to use an external site would mean one push to that site, then 20 fetches from that site from other places, hence only one transfer on the customer's limited link.

[Stefano]

a single mail with a 10 MB attach is, IMHO, big enough..

on all my servers I reject email bigger than 10/12 MB

since I guess you have a router/firewall in front of your SME, work on it.. even the cheapest one, nowadays, support band shaping

HTH

[purvis]

Only a few years back i had 2 dsl services coming into one location.

I did this to set up two networks. One dsl for a set of computers to access the internet from one wireless lan and another dsl to support a wired office to do all the other stuff. This was the only way i knew how keep some peace in the office. I did not double nat my routers and i knew nothing of double natting.

What was really crazy, was that originally i had 5 analog lines coming in to the location with one line having dsl service. I had my dsl service on the same line as our 5 line(the fax).
I ordered a new 6 line(the office staff had grown)  with a dsl connection.
Can you believe the 6 line with 2 dsl connections was cheaper than 5 lines with one dsl connection.
Bellsouth at that time had a price break on after having 5 lines.
It was just crazy to add a line and dsl and be paying 75 dollars less. I would of order 6 lines just to have a lower bill in the first place if i had know that.

My point, look into the priceing of your services. Getting more may cost you less.
If you are on a T1 line and that is causing your low upstream. You may be able to reduce your number of phone lines, there by increasing your internet speed and put one or more magic jack lines to use the internet.
Ps we are saving 17,000 dollars per year now by using one or two magic lines in all offices. All long distance phone calls are made on them.

There are routers that do have dual wan connections if you want to go with two dsl connections or you can still have a second dsl and use that as an internet gateway for web browsing.
For 20 people with slow internet, a second internet(dsl) connection or even a third connection would seem economical for most locations in the world with 20 people making use of the services.