Inbox delivery problems: how can you tell?

Last week we learned that most of our opt-in subscribers are NOT in fact clicking.

Before you can do something about that problem, you need to know where you're losing these subscribers in the sequence of events that starts with a sent email and ends with a click.

That's actually a very difficult task. For all our clever tools, we know very little about how people interact with our emails.

Do they even get them? Do they see them and delete without reading? If not, how much do they read? How long do they give us to capture a click before they move on to the next message? All questions that are tricky to answer.

But all is not lost...

Let's begin by looking at the first event in the chain: the email arriving in the inbox. Or not, as the case may be.

Most email campaign reports tell you how many emails went out and how many bounced back as undeliverable. We assume the difference is how many got delivered to inboxes. Not true.

A number of "legitimate" emails get silently deleted as "spam" before they get near an end user. And a number get through but are automatically diverted into the user's junk folders.

A mail that never gets seen has a pretty poor chance of garnering a click.

How can you tell if you have a hidden inbox delivery problem? Here are five techniques to use:

1. Intuition

Author John Naisbitt is quoted as saying:

"Intuition becomes increasingly valuable in the new information society precisely because there is so much data."

When you send out an email, you should have some pretty sensible expectations on its likely performance.

If the actual results fall well below expectations and for no obvious reason (like your ESP's tracking system died five minutes after your emails went out), then delivery problems are a likely candidate.

If the open rates on successive emails are 35%, 33%, 38%, 33%, 12%, then it's likely you had a delivery problem with your last email. (Or an even worse one than the one you have already, but don't know about.)

Even declining responses suggest that recipients are progressively turning away from your messages. Meaning that at some point they will start marking you as spam and your sender reputation (and delivery rates) will suffer as a result.

2. Domain segmentation

I covered this last month. If you look at your campaign results for all recipients sharing a particular email address domain, then you can spot anomalies.

If your email gets a 30% open rate, but your open rate among subscribers using an @hotmail.com address is 0%, then there are two explanations. Either Windows Live Hotmail users have got something against you or (much more likely) your email isn't reaching them.

3. Monitoring services

One tactic is to open email accounts at the popular address domains in your list, add these accounts to that list, and then check each after your campaign goes out.

It's a tiresome task though.

Fortunately, one woman's tiresome task is another's business opportunity and there are numerous services that will do the job for you.

Deliver Monitor and Delivery Watch are two standalone inbox delivery monitoring services. They give you a seed list of addresses to include in your mailings, then report on the results.

These reports normally tell you what percentage of your emails to leading domains like Gmail, Yahoo! Mail, AOL and others likely got through to the inbox, got filtered into the junk folder or got deleted en route.

This kind of monitoring is also commonly included in wider deliverability service packages offered by specialists like Lyris, EmailReach, Pivotal Veracity, Return Path, and others.

4. Proxy monitoring measures

Two other measures indicate a likely delivery problem (or an upcoming one).

The first is your presence on blacklists. While these blacklists vary in their practical relevance to your delivery success, suffice to say the more blacklists you appear on, the more delivery problems you're likely to have.

This page explains things in more detail and includes a list of standalone tools for checking your blacklist presence, as well as a list of leading blacklists (who will let you check their records directly).

Blacklist monitoring is also commonly part of the package offered by the inbox monitoring and deliverability services mentioned above.

The other proxy is to use feedback loops (FBLs) to monitor spam complaints leveled against your emails. Again, growing complaints suggest it's only a matter of time before ISPs start blocking your email (if they haven't done so already).

Feedback loops might be part of the standard service offered by your ESP or you can sign up to FBLs directly. See here for a list.

5. Deliverability testing tools

B2B email marketers are at a disadvantage. Inbox monitoring services inevitably focus on address domains favored by consumers (but don't forget that many business people use "consumer" webmail addresses, too.) And corporations don't offer feedback loops.

Are corporate spam filters accidentally catching your legitimate email? Fortunately, there are services that will give you some idea.

The main design testing services commonly include the results of tests against the more popular spam filters used by businesses. And, again, those commercial deliverability services listed earlier usually offer something similar, too.

Now being a swotty scientific type I have to warn that you will never get a perfect answer, whatever combination of tactics you use.

Spam filters at both ISP, corporate and user level, for example, have flexible settings. So monitoring services can only test against generic settings and not the full range of real-world alternatives.

Identifying a delivery problem is just the start, of course. Next week we'll look at how you might diagnose problems elsewhere in the email marketing chain. And then we'll look at what you can do to solve those problems...

Have you got any tips for identifying hidden delivery problems?

Tags: email marketing, email deliverability, inbox monitoring, spam filters

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