What is the limit that SMTP can do? 1

[ljCharlie]

I'm not sure if this topic relates to exchange server but I don't know which forum to ask so I choose this forum.

Anyway, I like to know what the maximum limit of emails that SMTP can send out at one time.

Any help, suggestionns, or point to a link is appreciated.

ljCharlie

 

[egnilk66]

Is this so you can send a bunch of spam to the rest of us??

 

[MoobyCow]

You can set the limits on the connector, but I guess the real hard limit would depend on your hardware.

 

[ljCharlie]

So what kinds of hardware or any kind of requirement do I need if I want to send around 10 to 40 thousand emails at one time?

I'm creating a news letter for interested users.

ljCharlie

 

[MoobyCow]

I can't say that I know what the requirements would be. The worst that will happen is that it will be real slow for a while as it churns out the email.

Maybe someone here has a server running that kind of traffic, otherwise you can call up sales at Microsoft and they'll walk you through specing out the server you need.

 

[PScottC]

Um... We're pumping about 15000 emails a week through our box and it's running Anti-Spam on top of IIS. This load is hardly causing a blip on the CPU for this box.

By default, IIS does only 100 simultaneous connections and queues the rest of the email until all emails have been delivered or re-queued due to connection failure. The SMTP engine will also take all available bandwidth to deliver, so I hope you're not planning anything else on your internet connection while the distribution is going on.

By default, the server will attempt to send again after 15minutes, then 30 minutes, then 60 minutes, then 240 minutes for every try after the 4th.

PSC

Governments and corporations need people like you and me. We are samurai. The keyboard cowboys. And all those other people out there who have no idea what's going on are the cattle. Mooo! --Mr. The Plague, from the movie "Hackers

 

[ljCharlie]

Thanks, PScottC, for the explanation. So while the SMTP is sending that 15,000 emails, it will slow down the whole network then, correc? Or we should not be doing any Internet access, correct? What about accessing our network resource, will that affect it too? You mentioned that you send out 15,000 emails a week, but how many emails each time?

ljCharlie

 

[PScottC]

The server in question is a mail relay for both inbound and outbound mail. So the 15000 is spread over 24 Hrs in 7 Days.

When I say you'll get slowness, I'm talking about your internet connection. If you drop 40K emails on the box simultaneously, it will begin sending to the internet right away. Figure out the size of your email, and multiply by the number then add about 300 Bytes for communication for each email. That's how much data you must push out of your internet connection.

You'll have to tweak the simultaneous connections setting on your IIS box to see how many threads you can run at the same time without pegging the CPU. On a decent box (2GHz+), I'll bet you could get 500-1000.

PSC

Governments and corporations need people like you and me. We are samurai. The keyboard cowboys. And all those other people out there who have no idea what's going on are the cattle. Mooo! --Mr. The Plague, from the movie "Hackers

 

[ljCharlie]

Many thanks for your help. The information you provided is very helpful.

ljCharlie