Any number of factors can cause an email to bounce back—from an unresponsive server or a full recipient inbox to an inaccurate or fake email address.
You and your team may have worked day and night for the last three months writing, polishing, and finalizing the company’s holiday email marketing campaign.
The whole company is abuzz with the potential for new customers, increased sales, and maximizing revenue.
The moment you hit send, though, the dreaded MAILER-DAEMON or other Mail Delivery Subsystem message hits your inbox. Or, the next day, your Non-Delivery Report (NDR) shows the damage.
The realization that your hard work was permanently undeliverable to the people it needed to reach? Not the best feeling.
Let’s take a closer look at what causes a hard bounceback like this, how you can prevent it with an email verification service, and how doing so can positively impact your marketing campaign and its ROI.
Where’s my email? Soft vs. hard bounces
Not all email bounce backs are the same, but they’re often preventable. Here’s a breakdown of the two main types––a soft bounce and a hard bounce––and why one may happen over the other.
As its name suggests, a soft bounce occurs when an email is temporarily undeliverable.
In this case, your ISP’s email server is trying to deliver the email message but isn’t able to immediately hand it off to the receiver’s email server. One of the following reasons could be inhibiting its delivery into their inbox:
- An unresponsive server or server outage
- The recipient’s inbox is full
- The recipient’s server can’t handle the size of the email
The good news is that email systems typically “retry” (continue to attempt to send) soft bouncing email messages for a period of time before giving up on them.
Hopefully, the soft bounce delay should only be temporary and your message may be delivered. Do note that if you resend an email several times and keep getting a soft bounce it could lead to a hard bounce.
A hard bounce indicates that your message failed to deliver for some permanent reason. Some of those reasons include:
- The email address doesn’t exist
- The email address is invalid
- The domain name is incorrect
- The message is oversized
- The recipient is unknown
- The message is believed to be spam or the ISP thinks you’re a spammer.
Too many hard bounces can cause your domain to end up on a blocklist. When this happens, a recipient’s email service provider (ESP) may block you, essentially treating you as a spammer.
Your sender reputation can take a hit as a result.
This can affect not only your current marketing campaign from reaching the appropriate inboxes, but it can also cause your general transactional emails (such as billing statements, shipping updates, etc.) to land in a client’s spam folder.
What happens when my email bounces?
Figuring out if an email has bounced or not
If you’ve ever received a “mail not delivered,” or a Delivery Status Notification (DSN) reply mail, then your message bounced.
In the case of a hard bounce, these auto-reply messages will typically show up in your inbox immediately.
Conversely, a soft bounce may take half a day or more. If or when it does show up, the message will sometimes include an error code.
For example, code 553 indicates a soft bounce, because there were too many recipients listed on the email.
Or, in the case of code 452, the recipient has insufficient storage. The important part is to figure out, first, if your message has bounced and then to figure out the type of bounce you’re dealing with.
Differentiating between a soft and hard bounce
At their core, the difference between a soft and hard bounce is their temporary or permanent undeliverable state, respectively.
You’ll know which bounce you’re dealing with by reading the content of the Non-Delivery Report or Receipt (NDR) and decoding what your email delivery errors mean.
In addition to some of the codes addressed above, looking for keywords like “permanent failure” in your bounce message or NDR is a clear sign you have a hard bounce on your hands.
Next steps after a hard bounce
Once a hard bounce happens, you have one clear plan of action—remove the defunct email address from your mailing list.
Leaving that address in place will only lead to another hard bounce, and in time, this could negatively affect your sender reputation.
If you experience a hard bounce (or several), there isn’t anything you can do to reverse this, as this is a permanent failed delivery. So, resending it would be a moot act. Save your energy and other resources by scrubbing the address from your list.
This may also be the push you need to prioritize looking after the hygiene of your email lists. Where there’s one obsolete address, there could be many more, especially if your lists are old or you haven’t sent emails to your subscribers for some time.
People abandon emails for many reasons: quitting a job, graduating, etc. Keeping your lists lean and clean is key to avoiding a hard bounce in the future.
Tips for avoiding hard bounce email addresses
If you want to keep hard bounces at bay, here are a few things you can do to save yourself time––and a headache or two––down the road.
Use a verification or double opt-in method for sign-ups
One way to keep your email lists disinfected from invalid emails is to offer your customers or subscribers a verification or double-opt-in method when they sign up for your services.
With a double-opt-in method, a potential customer will receive a confirmation email when they sign-up for your list. That’s if they input the correct email address, anyway.
This way, the onus is on the consumer to verify the accuracy of their email address. Once it reaches your list, you’ll know it’s legit.
Prioritize email verification before sending
Sometimes an ounce of (bounce) prevention is worth a pound of cure.
By ensuring your email lists are free from inaccurate, fake, or bot-run emails––before you send a single message––you could save a lot of time, and avoid failed deliveries.
Focus on the hygiene of your mailing lists
To avoid hard bounces, you must make sure that your email lists consist of authentic and valid addresses.
Remember, the number of email addresses on your mailing lists doesn’t matter—you want to keep the valid addresses, preferably those with owners who have previously engaged or are likely to do so in the future.
Checking emails manually often isn’t feasible, much less cost-effective for you or your company. An automated email verification process can continuously check the authenticity of your lists in real time.
Use an expert email verification service like Kickbox
To manually sift through hundreds of thousands of email addresses to determine which ones are legitimate would take more time and energy than you likely have. Not to mention the human-error component involved in such a meticulous process.
Case in point, many invalid email addresses don’t necessarily appear invalid on the surface.
Unless it’s a simple formatting issue, you’re rarely going to be able to determine whether an email address is valid simply by looking at it.
We all need an extra set of eyes at times, so think of an email verification service as insurance for your sender reputation. Delegate this process to a professional service like Kickbox.
In addition to the benefits of increased deliverability and engagement, you can also take advantage of its integration methods by importing, validating, and exporting figures and results from your preferred email tool or marketing platform.
Ready to make hard bounces a thing of the past?
The only thing that needs to be bouncing is you––when you head home after a long day at work.
Grooming your email lists and eliminating the dead weight of unused and invalid emails can help you avoid hard bounces while keeping your sender reputation in good standing.
Our team of experts at Kickbox can help you clean your email list with our real-time verification API. With over a decade of experience in compliance and the anti-spam industry, our team will become your team, there to guide you on your way to over 99% message deliverability.
It’s free to sign up. Let hard bounces and a bruised sender reputation be a thing of the past.