SMARTSIMS EMAIL POLICY FAQ
Last Updated 23 June 2017
Dear Mail System Administrator
You have been directed to this page because we are having difficulty sending email to students
at your organization. This prevents students from accessing our simulations to
complete their course-work.
Please whitelist the following SMTP mail servers:
- central6.netmike.com / 184.108.40.206 (primary)
- central7.netmike.com / 220.127.116.11 (backup)
Note: Our mail server addresses changed on 15 May 2013, so central2.netmike.com / 18.104.22.168 is no longer used.
The remainder of this page provides background information about who we are, what we do,
and why you should whitelist our SMTP servers.
Thanks for your help, and please feel free to email us on email@example.com
if you require further information.
Smartsims International Ltd.
Who / What is Smartsims?
Smartsims has provided online Business Simulations for University Courses and Corporate Training since 1997.
Teams of students run virtual companies and compete against each other online as part of their course-work.
What sort of email do you send from this SMTP server?
This server does NOT relay.
This server sends solicited emails only.
If we are sending email to your Institution, then that means:
- A Professor or Instructor at your Institution has decided to use one of our simulations in a Course
- That Professor has sent us a class list containing the email addresses of all the students
All email we send out relates specifically to that course. eg.
- Welcome Email containing initial login, password, and download instructions
- Billing / Invoice Emails (students pay us direct, so receive some correspondence)
- Professors also use our system during the semester to send course related emails to individuals, teams,
or the entire class list.
Ok, if you aren’t sending spam then why are you tripping my spam filters?
The two main reasons are:
- Our auto-generated emails are customized to each individual user (eg. unique login and password information).
So if a 300 student course at your institution uses our simulations, then we will send 300 *individual* welcome emails at once. This often trips spam connection rate checks at Institutions with larger courses.
Note: We try to set our default mail server delivery rate at a level which means that mail eventually gets delivered to most domains, even if it takes a few hours of retrying every 20-30 minutes. Unfortunately we don’t have enough fine control to adjust the delivery rate for individual destination domains if your default mail server tarpit / greylisting settings are more paranoid than that.
- The auto-generated email headers we use look a little bit simplistic for some Bayesian detection engines, so you may be getting an artificially high score.
Be more specific – where’s the failed smtp trace?
We may just be sending you this as a precaution. But if we have run into specific problems, we will send you a seperate email containing an smtp trace of the failure.
Tue 2009-02-17 22:23:14: <-- 250 2.1.0 firstname.lastname@example.org... Sender ok
Tue 2009-02-17 22:23:14: –> RCPT To: email@example.com
Tue 2009-02-17 22:23:54: <-- 451 4.7.1 Greylisting in action, please come back later
Tue 2009-02-17 22:23:54: –> QUIT
Tue 2009-02-17 22:23:54: <-- 221 2.0.0 mailchk-m03.blah.com closing connection
Why use ‘centralX.netmike.com’ instead of ‘centralX.smartsims.com’?
Our original Multi-Player product back in the 90s was known as NetMike.
The name just stuck for internal configuration and routing purposes.
We never send emails from firstname.lastname@example.org. We send from email@example.com
Do you have other SMTP servers?
Yes, but central6.netmike.com is the only one that sends out ‘bulk’ emails to an
entire class at a time. Our helpdesk runs off a different mail server, and since
they generally just reply to one student at a time we have no problems with
Sender Policy Framework (SPF) Policy
We have published an explicit SPF policy designating which servers are allowed
to send email from smartsims.com (and smartsims.in). We encourage all Mail System Administrators to
enable SPF checking and give favorable treatment to domains that explicitly pass.
SPF Best Practice for Sending Email on Behalf
Professors also send course related email to their class through our system. All email sent
from this SMTP server conforms to the
Sender Policy Framework Best Practices for sending email on behalf
eg. if Professor Smith sends email to his students through our system then the mail
header will contain the following:
That is sufficient to ensure that the SPF validation correctly occurs against smartsims.com rather than blah.com
Smartsims India Customers
The above notes also apply to our Smartsims India customers.
The only difference is that the designated Sender and Return-Path for customers in India is firstname.lastname@example.org rather than
If you have any technical questions about our services, you should still direct them to email@example.com