Tag Archives: email

MxToolbox Use Cases: Setting up a Mail Server

Setting up a Mail Server

Setting up a new mailserver can be a time-consuming and error-prone process, especially if it involves setting up a server for a new domain.  An administrator needs to balance new email security configurations with DNS setup, redundancy and firewalls.  While these can greatly improve security and email deliverability, they can complicate setup.

Here are a few suggestions for using MxToolbox to ease your mail server setup:

Pre-Check

  1. Run a blacklist check on the IP addresses that you plan to use for your server.  A blacklisted IP address should not be used for mail servers.

Verifying your Setup

We’ll start after you have assigned the IP addresses, and installed the OS and email server software.  From there you will want to verify that your server is up and running and accepting email:

  1. Run an SMTP test on each IP that will accept email.  This will perform several tests against your server and give you results on your SMTP configuration.
  2. Check that the appropriate Email TCP ports are available and responding through your firewalls to these servers.
    1. SMTP on port 25
    2. POP on 110 and 995
    3. IMAP on 143 and 993
    4. Outbound SMTP on 587
    5. OWA on 443
  3. Run a Port scan to make sure other ports are shutdown

Verify your DNS Setup

  1. Check your MX records to ensure they are pointing to the new server.
  2. Check that you have properly configured A records for the server.
  3. Check the servers PTR records to ensure they point back to the domain.
  4. Check your SPF records on the domain.

Final Setup

  1. Send us a test message.  Our Email Deliverability report will give you an in-depth report on email headers, hops and more.
  2. Setup your user lists.  We have an Email Extraction tool that can help you assemble simple lists of email users for addition to your server.

Advanced Testing

You might decide to adopt additional standards to address email delivery and spam issues.  MxToolbox is excited to offer tools that can analyze the setup of both DKIM and DMARC standards.

  1. Check your DKIM setup.  This can be useful for email deliverability as signing emails with a DKIM key can reduce bouncebacks.
  2. Check your DMARC setup.  DMARC can improve email delivery as a fully configured record gives recipients the means to communicate issues with your email.  If you monitor your abuse post, you can uncover and remove issues that might cause blacklisting.

On-Going Server Maintenance

We encourage our customers to setup a regular maintenance plan for their email servers.  Realistically, load issues arise, as do DNS and firewall complications.  The best way to prevent these is to know about them before they take out your email.  Here are a few recommendations to keep your servers up and running:

  1. Setup a Blacklist monitor for each IP address.  Blacklisting can cause lingering email delivery issues.  You want to know when your servers have been blacklisted.
  2. Setup monitors for your email systems MX and A records for this email server.  Typically, these shouldn’t change, but a monitor will ensure you know immediately if something does change.
  3. Setup SMTP monitors for IP address of each server.  SMTP monitors will constantly check your servers to ensure they are up to send and receive email.
  4. Setup a Mailflow monitor for each server.  Our premium Mailflow monitor constantly checks the end-to-end health of your mailservers by measuring traffic flow through the server.  

Monitors give you peace of mind.  You’ll know immediately when there is a service slowdown or outage and be free to concentrate on other issues.  

How can I make full use of my MxToolbox account? Part 3, Email

This is the third in our series on making the most of your MxToolbox account.  Today we’ll talk a little about email troubleshooting and what results you can receive from MxToolbox email lookups.

Email

As our name implies, MXToolbox started as a company dedicated to helping customers with email.  We continue that with our large number of email related tools and lookups.  There are several things you can do with our tools:

Test your Email Server’s DNS Setup

To receive email, you need to have MX records setup for a domain.  These can be setup to point to your ISP’s email services, a third-party email service like Gmail or Outlook.com or even an email server sitting in a backroom at your office.  Regardless, you need to make sure your MX records are properly setup or no email will find it’s way to you.   You can test you MX records with the MxToolbox SuperTool.

Test if your Email Server is ready to accept emailsmtp_example

Once your email server is online, you need to test it to see if it is accepting email.  Our SMTP test gives you multiple subtests to on your email server, including:

  • Open Relay – Whether or not your server is an open relay.  It should not be.
  • Reverse DNS Mismatch – DNS matches the IP address and there is PTR record pointing back from the IP address to the domain.
  • Valid Hostname – Checks that reverse DNS is a valid hostname for the DNS.
  • Banner Check – Checks that reverse DNS matches the SMTP Banner.
  • TLS – Checks that the server supports TLS encryption.
  • Connection Time – Checks connection time.
  • Transaction Time – Checks total transaction time.

Email Deliverability ReportLookup your Email Deliverability Settings

Once your email server is up and running and accepting email, the next question is will your email be accepted by your customers, partners and vendors.  Email delivery can be a challenge for companies, especially small companies getting started.   MxToolbox has several lookups that can give you insight into whether your email is deliverable or if your deliverability configuration is working beyond the basics of “Am I on a blacklist?”.

  • SPF – Check your SPF configuration, which specifies which servers are able to send from your domain.
  • DKIM – Verify that you DomainKeys Identified Mail setup is correct and accessible.
  • DMARC – Check your DMARC configuration to ensure that others can read it and send you rejected email from your servers and validate email coming from you.
  • Email Deliverability – See if your domain is on an email delivery problem list.

Analyze Email Headers

Sometimes email seems to work properly and yet a message takes days to arrive.  Sometimes you need to analyze a message to makes sure your system is processing everything correctly or investigate a suspicious email.  MxToolbox created a handy email header analyzer just for that purpose.   Header Analyzer takes your email headers and runs a complete analysis of hops, delays, and important email delivery information.  Use it to decode email delays!

In next topic of this series, we will discuss using DNS lookups.