Dodging the hard bounce

The dreaded email 'Hard bounce' - Monitoring your deliverability and taking action with your data

If you are a frequent user of email marketing, the idea of your messages not getting through to your customers is, of course, the very worst concept of all. It's the equivalent of your website going down or perhaps more analogous, your sales team being refused entry to your client’s offices.

So let's explore a few simple actions to try and alleviate the issue.

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There are 3 steps that need to be taken that can be put into three catchy words:

  • Identify - the hard bounce
  • Why - determine the cause 
  • Rectify - adjust the data

Before we take them in turn, let's very quickly define the difference between hard and soft bounce. 

Soft bounces are emails that are sent to a recognised and verified recipient, but don't get to them at the first send.

This is most likely because there was a server fault at the recipients end or the inbox was full. A last possibility was that your message was too large. If you use a recognised email delivery platform like Adestra, that software will try to get your message delivered by attempting resend, often a couple of times over a period of 48-72 hours. Then it will run a report. 

Email Hard Bounces are different. There are only two reasons that the hard bounce message isn’t arriving. 

1. The server does not exist
2. The email address is invalid 

(OK so tentatively there can be a 3rd reason in some cases some email systems/marketing automation tools will mark a hard bounce if the recipient has been marked with a cumulative amount of soft bounces this is a protective measure )

Either way, the poor data problem needs resolving, as it's giving you a false impression of campaign reach.  

Stage 1 - Identify

This is simple at one end of the process. If you use email software, a report should be at your fingertips. 

Alternatively, if you are using Outlook etc manually, you will have to create a suppression file by hand.

If you have a keen IT team/support function, they can look at the technical codes on each bounce to determine the reason. A guide can be found here for those technically minded.


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Stage 2 - Find out why

Your response will of course depend on the nature of the data errors. If your list is small you can ‘eyeball’ it for the most common problems, missing @ sign, misspellings of .com etc. There are products that can auto data cleanse for you or you may feel more secure using a quality data provider like Kompass for your email lists, for B2B Data it is particularly important to ensure you have optimum sourced data for exactly this reason.

You may have a lot of defunct companies. On average, a business changes name every 4-7 years, especially in the SME market,

The main thing with investigating poor data is finding the source of the problem. The most common reasons lay with poor data collection in the first place - which is why Kompass collect directly from source and don't scrape or aggregate.

You should undertake an audit of the following activities:

  • Web forms collecting data
  • Manual collection paper forms etc
  • Inputting into CRM/data sheets etc
  • Any external data – bought or rented etc, is it what it was billed to be - choose a solid provider

Often the problem is handwritten email addresses on forms that don’t leave space, allowing for human error.

So there are problems, but how bad are they? Mail engine provider Mailchimp has a set of standards and we can say from it that if more than 0.75% of your list is hard bounces then you are performing poorly. See all the breakdown by industry here.


Stage 3 – Rectify

Obviously. this follows on from your data audit. Solutions need to be crafted according to what the problems are. However, it would be very wise to run a complete review and refresh of data collection policy. Especially with GDPR just around the corner.

This of course could mean redesigned forms, but also briefings with your customer services teams. If your clients are giving wrong addresses it may pay to make it worth their while to incentivise them to give an alternative email, or that of a colleague. More often than not, if you tell them that this is in order that they can be addressed correctly in the future at point of collection, this normally assuages suspicions.

Paying attention to online web forms here is critical. If you have ecommerce, you may need to invest in an upgrade to a package that identifies basic email entry errors. I have found an article here about how the best US and UK retailers make sure that their customer is entering a valid email address.

Software can check for basic things like @ signs or suffixes that work (.com .org). It can also use cookies to populate the rest of the form with the user’s physical address, saving everyone’s time and gaining more data.

Double Opt-in

There are other steps you can take too, Each time you get a new customer/batch of customers you can send them a verification email. This acts as a check and also as a double opt in for you sending them information on your products/services. With GDPR this kind of best practice will be vital.

Lastly, keep monitoring your hard bounce rates – it’s the only way to make sure the actions you take are working.

Related articles10 Reasons why you need to refresh your data , A simplified guide to sourcing good data , /resources-gdpr-zone/gdpr-general-data-protection-regulation-will-it-be-a-friend-of-foe


Written by John Fenna, Head of Marketing,Communications & Digital at Tavistock Relationships


Disclaimer: Please note that this blog only contains general information and insights about legal matters. The information is not advice, and should not be treated as such.