Unusually large website traffic after Marketo email

[Anonymous]

Whenever we send out a large email (>30K recipients), our website gets hammered with traffic.  Something Marketo generates, as it not visitors from the mailing. We've checked all our Marketing email and landing page settings, all check ok. Can't figure out what could possibly be the cause?  Anybody else experiencing this, any ideas where to look?

[SanfordWhiteman]

Marketo doesn't hit your website when sending.

You aren't specifying *what pages* are being hit.

If it's the pages being linked in your email, nothing surprising about that, as mail scanners will pre-fetch your links.

[Anonymous]

Our site goes down every time we have a Marketo email send—something process is overloading our servers. This is not caused by direct user traffic to our site. We have not been able to figure out what is happening when the Email goes out from Marketo and why it is effecting our website—the only common thing here is the Munchkin code.

The larger the list we send to(roughly 30k), the longer the site goes down. Our host hasn't been able to pinpoint the source of the problem, but from their end, it look like we are running out of memory, and so far the Marketo techs have not been able to identify the specific error.

[SanfordWhiteman]

This is not caused by direct user traffic to our site.

It's surely caused by mail scanners hitting your site, together with you not having a robust enough infrastructure. That's what you should expect in 2017: you're going to get automated traffic as well as human engagement with your emails. Your site must be built for both: it's not enough to run a low-end server in the expectation that you'll only get a handful of human-opened sessions at a time.

the only common thing here is the Munchkin code.

The common thing is that you're advertising your site in messages that are processed by machines.

Loading Munchkin doesn't bring down your website, as Munchkin loads from and solely communicates with Marketo. Munchkin can potentially slow down page load when you use it in part-synchronous mode, but that isn't affecting your server.

it look like we are running out of memory

That's a symptom of not having a robust enough server to handle the simultaneously open connections.

so far the Marketo techs have not been able to identify the specific error.

Marketo can't solve a problem with your server being underpowered.

[Anonymous]

I appreciate the reply!

I think we need to look at the affect mail scanners are having on our site. Something to note too, is that we didn't have issues until about 4 months ago, so we need to look at what changed in our sends and on our site. We have sent to over 200,000 people without any issue in the past. We are still looking into it—our dedicated sever does not have any issues otherwise.

[Gerard_Donnell4]

I second what Sanford Whiteman​ said above.  Dan Stevens​ made a similar comment in a different post earlier with some links that might give a bit more detail.  You can see it here Setting up an alert, troubleshooting alerts. 

Do many of your 30k leads work for the same companies?  If you are sending the same email to hundreds of people in the same companies at the same time I reckon that would definitely be setting off spam filters and mail scanners.