Penetrating a business inbox can be more complex than perhaps people imagine. We all know that when we send an email to our client from our business email address that there is rarely ever an issue of it going anywhere other than their inbox. But when we send a marketing email from an Email Service Provider (ESP) not every email seems to arrive to the intended recipient.

According to ReturnPath one in five business emails never reaches the inbox. The rest is diverted to bulk folders (spam/junk) or lost eternally in the digital purgatory of cyber space. So how does an email actually get into a contact's inbox and why is it so difficult?  Here is a simple explanation below for those who are new to deliverability:

Inbox filtering

1. After an email is sent it has to be accepted into a company’s IT environment. To gain access the email will have its sender IP address checked for its sender score (an ISP and mail box rating out of 100 – 100 is the best) and the sender domain (e.g. If the sender domain is whitelisted and the IP address is 80 and above the email should make it through level one.

2.  Each company will have a different mail server (the agent that actually delivers your email). This mail server will check the content of your email (and subject line) for spammy copy, bad HTML and random/irrelevant URLs. It will also check the engagement history of all contacts in its data base that have received emails from you before. If no one has clicked on an email from you for 6 months and your content/HTML is dodgy, it is unlikely that you will pass gate 2 and your email will end up in the company spam folder.

Business Inbox

3. If you make it through level 1 and 2 your email then hits the mail box filters. These are filters that have been hard coded into the particular inbox when they were conceived, built and implemented. Outlook, Lotus Notes, Apple Mail, Entourage, all these inboxes have different innate filters ingrained within their make-up and can affect the journey of your email.

4. Beware of personally applied filters. Just because your email has made it past three levels of security does not mean it will land in the intended inbox. Recipients can set up manual filters that syphon your email into a different folder. An example is a Newsletter folder. Your email may be placed in there and not read for a couple of weeks until the recipient has time or remembers.


So that is a very simplified version of the processes your intrepid email must journey through in order to access the end recipient’s inbox. The even better news (for those that really like a challenge): every single company has different settings at every single level. This equates to a vast amount of potential combinations which are hindering your email deliverability. The solution – get granular: take notice of your Key Clients and how your emails are performing in view, click and bounce statistics. Through testing, trial and error you will optimise your performance.

If you are a professional services firm looking for a marketing platform with high-performing email capability, talk to Concep.