Undeliverable emails

What are Undeliverable Emails and How to Avoid Them?

Talk to any email marketer, and they’ll name email bounce backs and undeliverable emails as their worst nightmare. And rightly so. Imagine being enthusiastic and excited about an email marketing campaign, just to find out that 30% of your emails weren’t delivered.

Though email bounce back can be a serious problem, it can be resolved with a few methods. Here’s a detailed guide to what undeliverable emails are, what causes email bounce backs, and how you can avoid them.

What are undeliverable emails?

An undeliverable email is simply an email that couldn’t reach the inbox of the recipient. We also refer to such emails as bounced back emails. 

Bounced emails can be due to several reasons. Maybe you entered the wrong email address. It’s also possible that the recipient’s email client blocked the incoming email. 

No matter the cause, undeliverable emails can hurt your business. They can reduce your reach and deplete your email ROI. In fact, if your account’s bounce rate is high, it can adversely affect your email deliverability. 

Types of undeliverable emails

Undeliverable or bounced emails are of two types: soft bounces and hard bounces. 

A soft bounce means your email reached the inbox but failed to deliver. It could be because the size of your email was too large, the recipient’s mailbox was full, or the server was down. 

A hard bounce occurs when your email is rejected because the recipients’ email address was invalid. For example, if your recipients’ email address is “[email protected],” and you enter “[email protected],” your email will bounce back.

What causes undeliverable emails?

Some common reasons that can cause your emails to bounce back are:

1. Invalid email address

As discussed, hard email bounces include email bounces that occur when you enter an invalid email address. This can be due to a few reasons. It could’ve been a typing mistake at your end. Or, the recipient might have provided you with the wrong email addresses. Or, the email address would’ve existed before, but now it’s been shut down by the organization. 

Therefore, it’s always crucial to double-check an email before entering it to your email list. Since it’s not possible to identify the cause of bounce back, it’s better to check all the email addresses beforehand. 

2. Mailbox full

A full mailbox is a common cause of undeliverable emails. If your recipient’s inbox is filled with too many emails, they may not have enough storage to receive new emails. This issue is more common with contacts that use webmail services, as they come with limited storage. 

In some cases, filled mailboxes also indicate that the contact is not using the email address anymore. 

3. Email server unavailable

All emails are sent and received via servers. If your recipient’s email server crashes or under maintenance, your emails will bounce back. 

In this case, try sending an email to your contact after some time. If your email bounces back, again and again, it could mean the recipient’s server doesn’t exist anymore. 

4. Blocked email

Some contacts, mainly the ones that are a part of educational or government institutions, have strict guidelines for receiving emails. For such contacts, the receiving server can block your email from entering the recipient’s inbox. 

If you believe your email doesn’t violate the recipients’ email receiving guidelines, you can contact the system administrators and get access.

5. Blacklist

Many receiving servers use blacklists to filter incoming emails. If your domain or IP address is in the blacklist, your email will enter the spam folder, or it’ll bounce back. In either case, it’ll not reach the recipient’s inbox. Check out more about email blacklists.

6. Auto-reply

If your recipient has put his email account on auto-reply mode, your emails will bounce back. For example, your recipient could’ve gone on a vacation and put his account on auto-reply. 

This is a type of soft email bounce, which means your email reached the inbox of the recipient. To resolve this issue, you can try sending your recipient an email a few days later. However, if the story remains the same after a few months, it’s better to remove the contact from your list.

How to fix/avoid undeliverable emails?

If you’re running a mass email marketing campaign, completely eliminating undeliverable emails is impossible. As discussed, several factors can contribute to email bounce backs. So, if you’re sending out a bulk email to thousands of recipients, getting a few bounce backs is normal. 

What’s important is to keep an eye on your email bounce rate and make sure it doesn’t go too high. 

A study from Mailchimp suggested that the average hard bounce and soft bounce rate for an email marketing campaign is 0.58% and 0.93%, respectively. However, these numbers can vary. Another study suggested that 26-40% is an excellent bounce rate. To be on the safer side, let’s target 5-15%.

Calculate your bounce back rate

Calculating your email bounce rate isn’t difficult. Let’s say you sent 1,000 emails, of which 136 bounced back. The bounce rate, in this case, is 13.6%, which is high, but acceptable. 

Contact your list participants

If your bounce rate is too high, revise your email list. The chances are that most of your contacts are inactive, or they’ve blocked emails from you. 

The best approach to creating a successful email list is to contact your list participants via multiple channels. For example, get in touch with them on social media. This way, they’ll be able to inform you if they change their email address. 

Sometimes, bounce backs could be due to a problem with your email client. If your email servers are down, your emails will not reach their destination. Therefore, it’s vital to pick a trusted email client like Eltris for consistent email deliverability.

Conclusion: Undeliverable emails

It can be scary to discover that a quarter of your emails weren’t delivered. But by putting good email marketing and list building tactics into practice, you can easily reduce your bounce-back rates. Just make sure to keep checking your email list every now and then. Also, check out Eltris for a high-quality email hosting service with excellent deliverability.