Email Deliverability 101

Email deliverability is the measurement of emails that go to your Subscribers’ inboxes vs. spam/junk folders. You want to ensure your emails end up in your Subscribers’ inboxes, so high deliverability should be a critical focus.

You have the power to promote high deliverability by being Subscriber-focused. Send content consistently, and send content that they will actually want to engage with. Give them the power to choose how often they hear from you, providing opportunities for authentic engagement. All of these positive drivers will help you end up in more inboxes, and avoid spam folders.

How is deliverability measured? 

Many factors influence email deliverability. Generally, three questions are asked by mailbox providers (such as Yahoo, Google, Outlook, etc.) to determine what inbox an email ends up in.

• Is this message safe?
• Is it wanted by most Subscribers?
• Is the message wanted by this specific person?

If YES is the answer to all 3 questions, the email will most likely end up in the inbox. Otherwise, it will end up in spam.

What is your sender reputation? 

Mailbox providers rely on your sender reputation to create a ‘sender score’ using algorithms. There is not a one-size-fits-all approach to this, so each provider keeps their specific calculation and algorithms private, but one critical factor is how subscribers engage (or fail to engage) with your messages. How your subscribers interact with your mail is known as subscriber engagement. Their engagement with you can be positively or negatively impacted by subscriber behaviors. Here are a few tips for promoting positive subscriber engagement:

Subscriber List Health

• Focus on quality vs. quantity. Use subscribers who have given you explicit permission to communicate with them.
• Use a double opt-in or ReCaptcha for form security to prevent bot usage.
• Clean, or scrub, your list frequently of cold subscribers. Having a growing list of unengaged subscribers will drop your reputation as those emails start filtering to subscribers’ spam folders.

Consistency

• Try to not make sudden, drastic changes to the way you send messages, as mailbox providers will view these messages as risky, likely filtering them to spam.

• Using multiple domains is okay, but be sure they are recognizable and have been active within the last 6 months.

• Volume: send communications to a consistent number of subscribers.NOTE: it is normal for your list to grow or shrink, but try to not have any major swings (don’t jump from 2,000 subscribers one day to 10,000 overnight).If you have a large influx of subscribers, divide them into batches to slowly grow your database.

• NOTE: it is normal for your list to grow or shrink, but try to not have any major swings (don’t jump from 2,000 subscribers one day to 10,000 overnight).

• If you have a large influx of subscribers, divide them into batches to slowly grow your database.

• Frequency: Maintain your reputation by ending at least one email per month. If you go ‘dark’ for too long, your reputation won’t be maintained and you’ll essentially be starting from scratch with your next email. Contrarily, don’t send emails too frequently as it could be flagged as spam.NOTE: it is highly recommended to give your subscribers the option to determine how often they want to hear from you.

• NOTE: it is highly recommended to give your subscribers the option to determine how often they want to hear from you.

Content

Content influences your deliverability as an underlying data point, especially if you don’t have good consistency. If you send inconsistently, the actual content can be used to determine the safety and subscribers’ desire for your content. If you do send consistently, then content is often ignored.

Don’t use spammy words/phrases, or gimmicks. Try to make your email sound more conversational and human even if you’re selling something.

Don’t make it sound to urgent or overly promotional. Don’t use “tricky” subject likes like “RE: Your Order #12345” 

Eliminate link shorteners: these are often used by spammers and some spam filters may automatically red-flag these. Use the direct, full links for transparency.

Focus on your image-to-text ratio. While there isn’t a magic recipe here, the best practice is to have enough text so if an image fails to load, the text will still effectively communicate your message.

Drive authentic engagement: encourage your Subscribers to engage authentically. Maybe ask them to reply to your message with their favorite show they’re currently binge watching, their favorite song, or a great recipe they’ve recently cooked.

Frequently Asked Questions

1. Why Do I See “On Behalf Of” in My Email?

Certain email clients like Outlook desktop will display a notation referred to as “On Behalf Of” in specific circumstances. While perhaps not the best-looking arrangement - it is otherwise harmless. Please read the article below for more details. This generally occurs when sender email and from do not match. For example sender email = joe@m.example.com while From: joe@example.com. 

I-See-On-Behalf-Of-in-My-Email

2.  Why info@ email address not marked as invalid?

There are many factors that make an email address valid or invalid. The in-built email validation in Flow checks for the following:

• The email address syntax is correct.
• The domain is set up to receive email.
• The email address exists.
• The email address isn’t a high-risk address.
• The email address isn’t role-based, such as info@domain.com or admin@domain.com.

However, this doesn’t mean that an email address must pass all these criteria. The most important criteria is that the email must be deliverable. In the case of info@ emails, it’s considered a role-based email which is not a recommended email format because it can be perceived as spam, or bot since no person owns the email. But if the email is valid and deliverable, an email verifier will mark it as valid. For example, our email info@funnelbud.com is a valid email address even if it uses info.

3. Why it’s possible for email addresses from the same company to have different status?

Email validation checks individual emails. This makes it possible for emails belonging to the same company to have different status. One common example is if the person who owns the email has already left the company or if the email has been removed from the company server.

4. What does smtp_timeout means? Something with a server error..?

Smtp_timeout means it took longer than expected to connect to the smtp server. There are many reasons for this: server is temporarily unavailable, overloaded, network connectivity or restrictions, etc. It’s can be a temporary error and will resolve on its own.

However, if you keep getting the error, you’ll need to check with the your server admin to see why the connection attempt is being denied. 

5. What’s supposed to happen when you click Re-Verify Here? Can we verify email addresses by ourselves?

Flow email validation tool automatically re-validates all verified emails after 90 days. This applies to both valid and invalid emails. But yes, you can manually re-verify to check if the status of the email will change especially for email address with temporary validation errors.