Email Deliverability

Sending address health check

Email campaigns are, in the main, really easy to create and send but a common mistake we still regularly see is when ‘sending domains’ are not setup correctly.

We think it’s always worth spending a little extra time checking to ensure the email address you’re using to send has all the important pre-flight checks ticked off.

For the purposes of keeping this overview simple let’s assume you’ve got all the email authentication related stuff sorted and we’ll just focus on some of the more ‘obvious’ potential problems.

(DKIM, SPF, FBL etc. – well worth reading if you need a refresher on the technical setup side)

Branding (your reputation)

A good way to think about sender reputation is to try and understand what the person receiving your email thinks when they open it.

Designers give massive attention to detail ensuring websites are beautifully presented on all different browsers and mobile devices.

Likewise, Marketers need to give the same attention to email template design but before that, branding and sender reputation start with the domain(s) you chose for sending email campaigns.

Stay consistent with your brand with either a sub-domain like:

or,  a sound-a-like domain such as:

A few DNS records will have these setup in minutes and even better, it will keep your business email accounts completely separate and clear of any issues related to your email marketing campaigns.

A basic checklist

Choosing the correct domain is the first step because the last thing you would want is for your business email to be blocked because of issues your email marketing campaigns have caused.

Keep each type of emailing you do ring-fenced and keep your email marketing and transactional email away from the domain you use to send business emails from your Mac or PC.

This isn’t a complete list and none of the checks will magically increase delivery or response rates but every small improvement will combine to help you create better email marketing campaigns.

  • Don’t use ‘noreply’
    How would you feel about being told you can’t reply to an email?
  • Generic prefixes sound bad
    Group email addresses are a great way of managing incoming email but you should always be able to come up with a better sounding sending address. A lot of Spam is sent from ‘offers@…’, ‘sales@…’ and other similar sounding email addresses – avoid generics unless you really need to use this kind of name.
  • Stick to well known TLDs
    Unless you have a real good reason to choose something like over my stick to the more well-known version. Look in your junk folder and you’ll see that many of the messages in there are from  .info, .co, .biz etc. We still see emails sent from less well known domains being filtered and bounced.

Do some checks

Instiller has a number of really useful testing tools to help check sending domains and email templates for issues that could potential cause deliverability problems.

Litmus is great for not only seeing how emails look in different email applications but also for seeing the results from the most popular mail filters.

Monitoring the DNS records of sending domains is an important part of managing sender reputation as is ensuring you have signed up on all of the available Feedback Loops.

When you press send your email campaign is going to be sent using one or more IP addresses so keep an eye on your Return Path Sender Score.

For those that are more comfortable with DNS records there are some great testing tools out there but one of the easiest we’ve found to use is

Track clicks on the same domain

OK, so this suggestion might be overkill but given that every link within the email campaigns you send will be tracked then why not use the same domain as the sending domain?

From the point of view of mail filter checks it’s going to look a lot better as all the content will appear to be coming from and going to the same place.

Setup is easy, you’ll be setting up sending domain DNS records so adding one more entry for the click domain will only take you seconds.

What you’ll end up with is something like this:

  • Emails sent from
  • Clicks tracked using

Setting up a matching click domain is a much better approach than choosing to use a shared tracking domain as you can with other ESPs.


If you’re setting up email campaigns for multiple brands or you’re managing a service for clients it’s important that you setup sending and click domains for each.

Sharing sending and click domains across brands and clients means the impact of issues will reach through to anything the ISPs see as being related.

Creating an identity for your brand is what is important and once you’ve done that it needs to be properly managed to keep it well protected.

The point of all this?

Above everything else it’s about building and protecting your sender reputation.

Even with solutions like Instiller having a wide range of tools to setup and test each part of your email campaigns it’s still down to you / your agency to take responsibility.

It’s  not a big job and once it’s all setup, and being monitored correctly, there really isn’t much work for you to stay on top of things.

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