Five checks for fixing email delivery

Email is everywhere, and this has led to the false impression that email is simple technology. While email has been around for decades, getting an email from a sender to recipient is far from a simple process. There are many stages it must go through to travel from your outbound servers to your recipient’s inbox, and the more stages a process has the more chances there are for something to go wrong.

The problem is this: marketers are usually non-technical people, and so often don’t know where to start if they find that a portion of their emails aren’t being delivered. But by knowing some basics, troubleshooting your email deliverability is not difficult at all. Here’s a simple checklist of five areas to investigate if you find that your emails are not being delivered effectively:

Step one: check your sender reputation

Your reputation matters in a lot of areas, and email is one of them. Sender reputation is one of the key means by which internet service providers (ISPs) look to when considering how they will handle your email. Having a poor sender reputation will make it much more likely that your emails will be delivered to the spam folder, or not at all.

Sender reputation is something marketers can find difficult to maintain, as it can fluctuate from campaign to campaign. One email blast sent to the wrong segment can cause your reputation to nosedive and cause lasting damage to all your other email marketing efforts. It’s therefore really important to develop a process that ensures you have the basics covered. Make sure you’re employing double opt-in for your newsletter signup flow, and ensure there are clear and easy ways for your subscribers to opt out if they choose to. This may seem counter-intuitive, but ensuring a reader who wants to leave your list is able to is much better than keeping him on it: the latter will likely lead to complaints.

So how do you monitor your sender reputation? Senderscore andSenderbase are both useful tools for measuring reputation scores. If you see a big drop in your reputation as measured by these sites it might be time to take stock of what’s going on.

Step two: check your complaints

As an email sender, complaints are the last thing you want on your record: they send a strong message to ISPs that something isn’t right with the emails that you’re sending. If your recipients are sending complaints about the email they’re being sent it may be time to revisit the fundamentals of your overall email marketing strategy.

Take a look back at your email campaigns over the past three to six months: what has received the most engagement, and what hasn’t? Use this process to find out what kind of topics your readers are most interested in, and refocus your email campaigns around that. 

Of course, this kind of activity is useless if you don’t have any information on what your readers are interested in in the first place. Add some additional fields to your email signup form giving your readers a chance to state their interests in more detail - this will allow you to serve them content they’re more likely to be interested in and will reduce complaints.

Feedback loops are a handy tool for monitoring your complaint rates. Feedback loops used to only be used by ISPs, however they’ve now been opened up to senders as well. They can be quite complicated to use, so it’s worth checking what level of support your email service provides.

Step three: check you’re authenticated

Phishing remains a problem in email marketing, which is why authentication is important for an email sender. A phishing email is a fraudulent email that has been made to appear to have been sent by a trusted brand when it hasn’t. Authenticating your emails guards against this by proving that the email did in fact come from you. Think of it like a signature.

If there’s doubt over your email ‘signature’, or if you don’t have one, then your email may not be delivered successfully. When you sign your email with SPF and/or DKIM, you’re giving ISPs more information about where your email should be coming from. Always make sure your email is authenticated so that your email doesn’t get wrongfully caught in an  ISPs’ net.

Step four: check if your IP is “warm”

So far, I’ve talked about how to manage your sender reputation and mitigate damage to it. However what if you’re starting with no reputation at all? This is the situation that faces marketers who have a new IP address.

ISPs track your reputation based on IP, so if you’ve recently changed it then they will have no information on you. This doesn’t necessarily mean that your email will automatically land in spam, but if you have recently changed your IP address and have been experiencing delivery problems, this is the most likely reason why.

There’s no easy way to deal with this problem: you’ve just got to ride it out. Continue sending from your new IP in gradually increasing levels of activity and you’ll begin to build a sender reputation up for yourself. This process is called “warming an IP” and is very important - if you don’t do this in a gradual manner and start sending email in bulk from a ‘cold’ IP you may find yourself blacklisted.

Step five: check you’re not blacklisted

Blacklisting - the ‘nuclear option’. If ISPs receive enough complaints about you they may put you on a blacklist. When you’re blacklisted you’ll find it very difficult to deliver email to recipients from certain ISPs. Luckily there are several websites that publish ISP blacklists, so if you think you might be blacklisted it’s well worth checking via one of these sites: Spamhaus; SURBL; Barracuda Reputation Block List; Invalument; Spamcop; MultiRBL.

If you’re on a blacklist ISPs want to see you be proactive about trying to get off it. ISPs are run by people after all - show willingness to learn and improve your email marketing and it’ll put you in good stead. Opening these lines of communication with ISPs will serve you well in the future as well.

It’s important to remember that, no matter what service you use, you will never deliver every single email that you send. Due to having so many steps in the process, some emails are bound to be lost in the shuffle. There’s only cause for concern if you start seeing consistently high proportions of your email not being delivered; in this case there may be a problem with your sender reputation, but, as this checklist shows, there’s always something you can do about it.