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People often have a misunderstanding between deliverability and email delivery. While Delivery issues mean that something may be wrong with your email list, deliverability is concerned with whether you have a permission and relevant content or not.

Email deliverability is a way to measure how successful you are at getting a campaign (an email) into a subscriber's inbox. It involves anything that touches email delivery, like ISPs, MTAs, throttling, bounces, and spam filtering. According to Hubspot, email Deliverability is affected by three aspects:

The source of the addresses

Rented or purchased lists are not always a good email practice. You don't know who are the people in this list, what are their problems or aspirations. You don't even.know if they're interested in hearing from particularly.

The permissions required

So sending an email will be like inviting yourself to a dinner in your neighbor's home and telling yourself they are generous enough and want me in while you might be absolutely unwanted. In a short, people don't love surprises. And requesting their permission is not hard anyway, it could be anything from a subscription to a newsletter or a request to download and eBook. There are a lot of tricks to obtain your user's confirmation especially if you know you’re their needs, pains and emotional triggers.

The expectations set

And even if you have their permission you still need to tell them what to expect. Is it sales offers? Daily news? Some cool graphics every week?. And When they should expect you to approach them and what's the frequency of that?. You need to set expectations with your recipients while they're still optioning-in you so you don't lose them along the process and turn them into enemies or brand haters.

How to avoid bad deliverability?

Use double opt-ins

Using the double opt-in process may slow down the process a little or decrease your list growth but on the other hand it will keep your list healthy. People who would go through double-opt-in process must be interested in receiving your content and will tend to engage more. You are going to build a list of much more qualified leads that are more likely to lead you to a return on your investment of time spent marketing to them.

Avoid spam trigger words

One of easiest ways to avoid spam filters is by carefully choosing the words you use in your email's subject line. A good rule of thumb is this: If it sounds like something a used car salesman would say, it's probably a spam trigger word. Think "free," "guarantee," no obligation," and so on.

In the email deliverability world, you should be monitoring your open, opt-in / out, spam and many other rates. You will never know about your email performance unless you see how many of them bounces and track the reasons why this happened.

Measuring deliverability after send

Without measurement you’re blind but if you did it wrong you will get irrelevant results that might lead to campaign disasters. Generally, there are two different types of measurements. You can track your engagement metrics like clicks and opens. These small actions indicate that your recipients were attracted enough to do something. The other way could be measuring your contact churn rates like counting the emails that bounces with every campaign and categorizing them to recipient's bounces, content bounces, reputations bounces, and temporary bounces.

The bounce codes starting ones starting with 4 means that it's a temporary bounce and you can try again. Note that a temporary or soft bounce may turn into a hard one if not delivered in 72 hours. While Codes starting with a five means you should never try again because it will never work.

Finally, be aware of where your bounces coming from, source, form, list and conversion type.

Clean your list

Even if your list is entirely built in legal ways and by obtaining recipient's permissions, you can still be marked as a spammer if you don’t clean your list properly because internet service providers (ISPs) base complaint rates on active subscribers, not total the next time you observe see low deliverability rates, you should consider cleaning your list at first. Permissions and email addresses expire. Large numbers of your list gradually turn into inactive users and your list might be including spam traps. So you might have the right content and design this time but still won't hit.

Check for wrong formatting, spelling and punctuation

Did you ever receive and email with a lot of caps and exclamation marks with a message like " GET 50% OFF NOW!!!!" and actually opened it? Yeah right, probably not. And This might sound unrealistic but it does happen as 69% of email recipients report email as spam based solely on the subject line, because of such spammy words.

Ask your subscribers to add you to their lists

If you’re sure that your recipients are interested in hearing from you, ask them to add you to their whitelist so they never miss any of your emails and at the same time avoid spam triggers once and for all. This should be used with servers using greylist techniques.

Wisely use images

Using too many images in your design or one big image as your email will eventually end up as a spam compliant. Not to mention, Microsoft Outlook doesn't recognize background images, so you may want to avoid those and use a background color instead.

Include feedback forms

This will let you discover a lot about your recipients. What are the issues they face, how and why they might even mark you as a spam.

External elements that might lead to bad deliverability

Inbox is full

Bounces could be a typical indication that the email recipient's inbox is full and cannot accept any more messages. There is little you can do to resolve this error message unless you have another means of contacting that person to notify them of the full inbox. They should usually be able to resolve this issue by deleting old emails or raising their current mailbox quota.

Send limit exceeded

On all of our shared servers, the number of emails that can be sent per hour is limited to 250 per hour with a additional limitation of 50 recipients per message (this includes To:, Cc: and Bcc: fields). If you attempt to exceed that amount you will receive a bounce back that will say something similar to: "Domain has exceeded the max emails per hour (250) allowed. Message discarded." If you would like to request that this amount be increased, you can make that request that within your AMP account. ( advanced malware protection).

Permission Denied

This means the recipient's mail server mistakenly thinks you’re spam, or malware, and is protecting itself by refusing to accept any of your content. To solve this, you’ll need to contact whoever manages your mail server, or hosts your email address, as somewhere along the line your mail server could’ve got a bad reputation.

Temporary Failures: 400 Errors

A failure between the 400’s means that either the target server is down and not accepting connections, or that the server is temporarily refusing to accept the mail, but might accept it later. Excluding many free, or bulk email providers, mail servers will usually try for up to 5 days before giving up. After 4 hours, a notice is normally sent back to the sender explaining why there is a delay; at the end of 5 days, a final delivery failure message is sent back to the sender.

How spam and deliverability affects your business?

You might be thinking to yourself that we’re exaggerating, it's just an email right? Well, according to Microsoft’s Justin Rao and Google’s David Reiley, spam costs the global economy close to $20 billion every year in lost productivity while spammers as a whole make about $200 million per year. Huge right! But how this happens?

It costs virtually nothing for spammers to send out large bulk mailings to tens of thousands of unwilling recipients. Shockingly enough, only 1 in 25,000 spam recipients need to buy a product or service through spam advertising for it to be profitable. Naturally, these kinds of numbers would never work in direct-mail advertising campaigns.

Spam email equates to a genuine waste of employees’ time. On average, employees take about 16 seconds to go through and delete each spam email (source: Nucleus Research). If the business doesn’t have a spam-filtering service, then up to 70% of an employee’s incoming emails per day could be spam messages. So, 70 % of (x) incoming emails times 16 seconds times the number of employees in your business would equal to X wasted man hours per day.

Spams can ruin your business reputation. Away from the IP issues, your brand might be known for being spammy and this will certainly reduce your sales affecting your business profits.Additionally- and as we discussed earlier- spam emails are illegal and the payments made as a compensation for it could reach millions.

Spam and deliverability