Email deliverability best practice

Why do some of your emails not get delivered to the recipient, and how can you fix it?

Do you ever feel like your emails are just bouncing around, never actually reaching their intended destination? If so, you’re not alone. In fact, it’s a common problem that can have a number of different causes. In this blog post, we will look into the most common reasons for email deliverability issues and what you can do to fix them.

Common reasons your email bounces

  1. The email address is incorrect when they signed up.

    People populate web forms with inaccurate information from computers, tablets, or smartphones. Also, when clerks transcribe handwritten addresses onto a point-of-sale system form, they sometimes introduce errors.

  2. The message is blocked by the server because it goes against one of its rules.

    Messages may be subject to filtering if they come from an email address that isn’t authorised by the target’s administrator. The message might be too long or formatted incorrectly, include prohibited material, or be from a banned domain. In some instances, the message is acceptable, but you accidentally sent it to a spam trap, an email address set up to receive unsolicited emails.

  3. The mailbox of the person you are trying to email does not exist.

    A missing mailbox might be empty or belong to a closed account. In order to enter a contest or download material without subscribing to your email, your subscriber may have deliberately entered incorrect data. She could also have closed her AOL account and transferred to Gmail.
    Because you don’t know how many of those addresses are still active until you send them, you’re prone to this mistake if you purchase or rent email address lists.
    When an email address is no longer active, soft bounces may occur. This happens when the mailbox becomes overloaded with messages and can’t accept them anymore. Even though the mailbox is still technically valid, its full capacity prevents any new messages from coming in.

  4. Your IP address is blocked by the server.

    This is a permanent problem. It’s caused by a variety of factors, including the following: Your IP address has been blacklisted for spamming or email fraud, or it has other reputation issues. You’re using an insecure internet connection, such as a public Wi-Fi network. Your email service provider has a bad reputation.

  5. The server is currently under a significant strain or Offline.

    A soft bounce occurs when the preceding bounce is not addressed. The issue isn’t with your email system, your IP address, or the message itself; it’s something on the recipient’s end. These servers typically keep messages in a queue before delivering them once the issue has been resolved.

How to prevent email bounces and improve email deliverability

Bounces are unavoidable, but there are several tactics to reduce your risk and improve email delivery.

  1. Use Double Opt-In

    With double opt-in, new subscribers must confirm their subscription by clicking on a link in an email you send them before they’re added to your list. This ensures that people only sign up for emails if they’re actually interested in receiving them, which reduces the chances of undeliverable email addresses.

  2. Keep Your Lists Clean

    Even with double opt-in, your list will slowly become outdated as people change jobs, switch email providers, and unsubscribe from your emails. To keep your lists clean and up-to-date, you should regularly remove bounced addresses and unsubscribes. You can also use a service like NeverBounce to verify email addresses before you add them to your list.

  3. Use a Professional Email Service Provider

    If you’re serious about email marketing, you should use a professional email service provider (ESP) like MailChimp, Constant Contact, or Active Campaign. These services will help you avoid many common mistakes, including using insecure IP addresses and poor list hygiene. Plus, they provide detailed reports on your email campaign performance, so you can quickly identify and fix any delivery issues.

  4. Follow Email Marketing Best Practices

    There are a number of best practices you should follow to improve your email deliverability, including using a consistent “from” name and email address, avoiding spammy words and phrases, and keeping your emails short and to the point. For more tips, check out our guide to email marketing best practices.

  5. After the opt-in, send confirmation emails

    For example, if you have a lot of emails in your inbox and want to delete them all at once, this step will eliminate any that are invalid.

  6. Sign up for ISP feedback loops if you haven’t already

    If a recipient clicks the spam button on your message, ISPs will see it and include this in their reporting. You may have all of your messages blocked if you continue to send them to complaining addresses.

  7. Keep a close eye on your email delivery reports

    The error codes your emails triggered will be recorded in these reports, which can offer varying degrees of accuracy or clarity when it comes to identifying the problem. Get assistance from your database manager while reading the reports and interpreting the codes.

  8. Keep an eye on email delivery by domain

    If you realise that a certain ISP is preventing your emails, you can quickly get to the heart of the issue. Many ISPs have protocols for solving problems on their websites already gathered in one place.

  9. Remove invalid, duplicate, or inactive addresses from your list on a regular basis

    Moving dormant email addresses off your active list and developing a reactivation program for them is an effective approach to avoid soft-bouncing. Address that bounce frequently might be abandoned mailboxes that should be converted into ISP or blacklist spam traps. Remove inactive accounts from your active list and set up a reactivation program for them.

There is no one-size-fits-all rule for removing hard and soft bounces from your file. It depends on the situation with each firm. Bounces are an important component in every email marketing campaign since they directly influence your “score” or “reputation” with the ISPs.

The terms “hard” and “soft” are important to consider when evaluating the bounce rate.
If you get a 4XX code when attempting to email someone, that’s considered a soft bounce. These are OK depending on the specific code, and you might be able to retry contacting these email addresses several times before giving up. If you receive a 5XX error code, however, this is classified as a hard bounce and requires your immediate attention. Overall, you should make sure that you always have a clear list with people who actually want to hear from you. The best practice would be to clean your lists after each campaign ends.


Email marketing can be a great way to reach your target audience, but only if you’re following email deliverability best practices. Make sure you’re using a professional email service provider, and following email marketing best practices, to ensure successful delivery of your emails. Also, keep an eye on your email delivery reports, and remove any invalid or inactive addresses from your list on a regular basis. Doing these things will help you improve your email deliverability and following best practice which ultimately, will ensure that your messages are reaching the right people.