What happens when your email bounces?
Before we get into what an Email bounce means, let’s take a look at how email works.
Briefly speaking, when you hit the ‘send’ button, your email passes through several servers, gets into a queue waiting to be processed, before it is finally delivered to the destination. However, it doesn’t always reach the destination. Some emails tend to bounce for various reasons, which will be explained below. When you view your real-time reports on Pepipost, you’ll realize that few emails have ‘bounced’.
So, what is an email bounce?
When an email delivery to the subscriber or recipient fails, it is known as a ‘bounce’. The sender receives an email immediately indicating the email bounce. There are number of reasons why an email bounces. Usually, the bounce message, in the email, will give you information identifying the reason why the bounce occured. The main categories under which an email bounce occurs is either Soft bounce or Hard Bounce
- Soft Bounce means this is a temporary delivery issue which can be fixed with or without any changes to the email itself. This also means that the email Id was valid and the email reached the recipient’s mail server. However, it bounced back it because of the following reasons –
- The email message was too long
- Inbox was full ( reached the maximum quota )
- Recipient email server is down or offline
In this case, either check with the recipient to resolve issue on their end regarding inbox space and/or try to resend the email again. If the email continues to soft bounce in campaigns, the email ID can be discontinued for further campaigns.
- Hard bounce is a permanent issue as an email cannot be delivered. Hard bounce occurs when the email is completely rejected and cannot reach the recipients server for the following reasons,
- The email ID is invalid or mistyped email address
- Non-existence of the recipient’s domain or unknown recipient
- Recipient email server has blocked delivery
- A network glitch at the recipient’s end
Actively managing your bounces is very critical, in case of hard bounces, you could delete the email addresses, but deactivating them or adding them to a suppression list is highly suggested. This ensures that you will not accidentally send mails to email addresses that you know will hard bounce.
What do you mean by email bounce?
An email that cannot be delivered to the intended recipient is said to have bounced. At Pepipost, there are two types of bounces we report.
- Soft (temporary) bounce: In this case, even though the email address is recognised by the recipient’s mail server, the email cannot be delivered and is returned back to the sender. There could be many reasons for this – mailbox full, message too large, mail server temporarily unavailable, etc.
- Hard (permanent) bounce: Occurs when recipient email address is invalid/ terminated or when the domain name doesn’t exist. While most cases of hard bounce occur due to invalid email address, there may be instances when emails get rejected because you haven’t done SPF configuration on your DNS account. You need to define IP in TXT records to allow Pepipost servers to send emails on your behalf.
Why do emails bounces need to be managed?
Email marketers generally focus on monitoring open rates and link clicks, whereas looking at bounces would be similar to crystal gazing. You can deduce the impending deliverability problems.
While a soft bounce is not critical as the message usually gets delivered at a later point in time. However, hard bounce plays an important role in email deliverability and needs to be closely monitored and managed. Bounced emails should be under 5% of the total emails sent and anything over 10% is a red flag that should be investigated.
How does one know exactly why the email got rejected?
The response from remote server will give you a good insight as to why an email could not be delivered to a particular recipient. Here are two cases to explain how an email bounce notification may look like;
1.If the Email Address is disabled by Gmail or the recipient/subscriber. Then, the bounce notification will look something like this:
The response from the remote server was:
550 5.2.1 The email account that you tried to reach is disabled. Learn more at https://support.google.com/mail/?p=DisabledUser17si15813694wmv.65– gsmtp
Final-Recipient: rfc822; email@example.com
Remote-MTA: dns; gmail-smtp-in.l.google.com. (2a00:1450:400c:c04::1a, the
server for the domain gmail.com.)
Diagnostic-Code: smtp; 550-5.2.1 The email account that you tried to reach is disabled. Learn more at 550 5.2.1 https://support.google.com/mail/?p=DisabledUser 17si15813694wmv.65 – gsmtp
Last-Attempt-Date: Wed, 01 Mar 2017 02:22:32 -0800 (PST)
2. If the Email Address doesn’t exist at all i.e. its INVALID then the bounce notification will look something like this:
The response from the remote server was:
550 5.1.1 The email account that you tried to reach does not exist. Please try double-checking the recipient’s email address for typos or unnecessary spaces. Learn more at https://support.google.com/mail/?p=NoSuchUser k98si4186592wrc.76 – gsmtp
Final-Recipient: rfc822; firstname.lastname@example.org
Remote-MTA: dns; gmail-smtp-in.l.google.com. (2a00:1450:400c:c0b::1a, the
server for the domain gmail.com.)
Diagnostic-Code: smtp; 550-5.1.1 The email account that you tried to reach does not exist. Please try
550-5.1.1 double-checking the recipient’s email address for typos or
550-5.1.1 unnecessary spaces. Learn more at
550 5.1.1 https://support.google.com/mail/?p=NoSuchUser k98si4186592wrc.76 – gsmtp
Last-Attempt-Date: Wed, 01 Mar 2017 02:24:28 -0800 (PST)
In both of the above mentioned cases, the emails are being rejected and the recipient server (here in this case it’s Gmail), returns a 550 series permanent fatal error:
In case 1: 550 5.2.1 The email account that you tried to reach is disabled. Learn more at https://support.google.com/mail/?p=DisabledUser17si15813694wmv.65 – gsmtp.
In case 2: 550 5.1.1 The email account that you tried to reach does not exist. Please try double-checking the recipient’s email address for typos or unnecessary spaces. Learn more at https://support.google.com/mail/?p=NoSuchUser k98si4186592wrc.76 – gsmtp
For your reference, here are the other types of Gmail Error Messages: https://support.google.com/a/answer/3726730?hl=en
How Google (and other ISPs) decide the fate of your email
You may have observed one another parameter that Gmail is recording Last-Attempt-Date.
This is a very critical parameter. The Date and Time when you last attempted to send an email to an email address is recorded. Along with this, the IP address, sender domain and other message details/patterns are also being recorded. Note these scenarios:
- Google will observe if a sender is making multiple attempts to the same recipient email address. A person with an in-house infrastructure to send emails may have no way of knowing that a certain email bounced and will continue to send emails to that email address. Even if the in-house system has the ability to track the bounces, you wouldn’t know about the type of bounces and would hardly take any action to rectify it.
- Some use multiple ESPs to send their emails. While ESPs have a mechanism to block the email IDs that hard bounce, they would in no way know that the email address was blocked by the other ESP and hence, the attempt to that particular email address will happen through multiple pipes.
- You change the sender domain frequently to bypass the Anti-Spam filters. But, wait Spam Filters are much smarter than you. They will track the pattern of the content too.
“Instead of every time putting efforts to hack Anti-Spam filters with your smartness, try to incorporate the best email practices.”
How can you reduce email bounces in the future?
Incorporate these practices to reduce email bounces in the
- Update your list regularly – Promote your subscribers to update their information at their end by filling survey forms. Rid your list of invalid emails and non-responders.
- Maintain a good list-hygiene – Check your lists for incorrectly formatted email addresses, invalid domains, typos and “spam flag” email addresses. You can either do this manually or with a list-hygiene service. High bounce rates can affect your sender reputation, cleaning up your lists can help you reach a higher email delivery rates.
- Use double ot-in campaigns – Send a confirmation email to the users when they subscribe to your list. This way you can ensure that the subscribers email is not only valid, but also want to receive your emails. A confirmed opt-in is far better than a single opt-in.
- Pre test your emails – Send a test email to yourself and a small test group to check if the email is landing in the spam folder. Duly monitor spam filters, excessive use of punctuation, overly promotional or clickbait centered words should be avoided or worded well, so your email doesn’t end up being marked as Spam.
- Stay off Google radar – Google tracks hard bounces and if you send emails too often with the same message style or source IP or sender domain, it will consider your mails as spam. Ignoring the bounce message can soon lead to having your email blocked from sending to any other email address for a certain amount of time from the same IP address used to send the mails. This can last for couple of days or even up to a month, depending upon the critical nature of the situation.
Such poor management of hard bounces would affect the reputation sender domain and also the delivery IP address of the ESP.
We here at Pepipost are on a mission to build a cleaner email eco-system and are putting efforts to bring awareness and encourage good email sending practices.
As a Global Email Service Provider, we keep our policies compliant with other ISPs and Anti-spam filters. In case you are using Pepipost, then relax. If not, then either start following these best practices to protect the reputation of your emails or switch to Pepipost and join the fastest growing good email senders community.
Found this blog useful? Please rate us
Pokemon Go, the immensely popular augmented reality video game that has taken the word by…Read More