Antispam, Deliverability

Hard bounce, Soft bounce, Spambounce, Deferred and OK: what are email statuses and how to interpret them correctly?

Natalia Zacholska, 30 July 2021

eEmail statuses available in the EmailLabs panel are a great source of information about our campaigns. Thanks to them, in case of worsening results, we can identify all problems and quickly eliminate them. However, this is possible only on one condition. we must be able to interpret the available data. Thus, to make this seemingly complicated task easier, we have prepared a special guide presenting a set of basic email statuses (of course there are many more statuses available in the EmaiLabs dashboard), explaining what each of them means and how to interpret them correctly to maintain high deliverability.

Email statuses and email logs in the EmailLabs dashboard

EmailLabs system collects statuses of each executed campaign, keeping them for an indefinite period, so the client can easily access historical statistical data at any time. Yet, detailed message logs, e.g. date and time of sending, subject of the message, To, From, Message_id, status, provider feedback, information about opening the message or clicking on the link (time and date of this action) are exceptions – this information is archived (depending on the customer package) for 7 or 15 days. Moreover, any EmailLabs user can retrieve all statuses (except Injected) from the panel using the provided API.

For this purpose, EmailLabs has provided a Webhook function, i.e. integration via API, thanks to which the client can download all (except for Injected statuses) data collected in the panel directly to their systems. Who should be interested in such a solution? In fact, any company that cares about extended analytical, control or security capabilities. Webhook collects data within its mailing system and allows for detailed analysis of statuses and logs, which are unavailable in the EmailLabs system due to time limitations, even after several months back.

Glossary of the most important email statuses in the EmailLabs dashboard


The OK status, sometimes called Delivered by other ISPs (Inbox service providers), means that the message has been delivered to the receiving server. It is worth noting that you do not receive any feedback regarding which folder the message has been assigned to – in this case, the receiving server has a couple of options: it will either deliver an email to the inbox or in folders such as Offers, Newsletters, etc. or it will classify it as Spam. Much more rarely, the receiving server decides to drop the message (Dropped status), which often means removing it from the server altogether.

Soft bounce

A soft bounce is a status indicating that the message was not delivered to the recipient. In other words, the sending server (EmailLabs) has established a connection with the receiving server, but the latter one could not accept the message at that moment. There can be several reasons for this, including mailbox over quota, the recipient’s server is down, or the message is too large. Yet, it is worth noting that Soft bounce status does not imply the address is saved on the internal EmailLabs Blacklist, and if the customers want to resend a message, they have to do it themselves – resending is automatic only in the case of an intermediate status such as Deferred.

Hard bounce

A hard bounce indicates that an email has not been delivered because the address to which it was sent simply does not exist, is invalid, or the recipient has email delivery blocked. Such an email address is recorded on the internal Blacklist in the EmailLabs dashboard and blocked at the system level. In this way, we limit the number of hard bounces in subsequent mailings, protecting the reputation of the server and the sending domain. At the same time, it is also possible to export such email addresses, so the user can easily remove all inactive records on his side, which promotes high hygiene of the contact database as a result.


Spambounce is an information for the sender indicating that his message has been recognized as a potential Spam, and the receiving server did not accept it, so the recipient will not even find it in the Spam tab.This situation is usually caused by elements such as wrong text to graphics ratio, vocabulary, attachments, domain and server reputation or frequency of sending, that indicate that we are dealing with an unwanted message. Yet, it should be noted that addresses with a spam bounce status are not saved on the internal EmailLabs Blacklist.


Deferred is an intermediate status that appears when the EmailLabs system is unable to establish a connection with the receiving server. This can be caused by exceeding the limits imposed by a provider. In this case, the message is sent again and again over the next 48 hours and if a message is still not delivered, one of the final statuses is assigned (i.e. Spambounce, Hard bounce or Soft bounce). However, if the server accepts the message, the status OK is given, which means that the email was successfully received.

Why is it really important to track email statuses?

Some companies mistakenly limit their analysis to the open-rate (OR), which in terms of deliverability will tell us nothing whatsoever about possible reputation problems or negative audience engagement. It’s worth noting that we should rather use OR for A/B testing and campaign comparisons. Yet, CTR will certainly be a much better indicator for analyzing the effectiveness of e-mails. However, we should always look at what could have happened along the whole process of communication delivery, and that can only be done by analyzing a range of available statuses, not only OR or CTR.

Thanks to the statuses we will also have full information about the hygiene of our contact base, which is crucial to ensure high deliverability. We should always be aware that an excessive number of Hard bounces may indicate that our database contains many inactive and incorrect email addresses. On the other hand, an excessive number of Soft bounces may imply an urgent need to configure one of the authentications (SPF or DKIM); if we add them correctly, our deliverability will surely increase.

EmailLabs continuously monitors marketing and transactional emails, verifying their deliverability, which is calculated based on their OK and Injected statuses – for transactional emails the average deliverability is 99.98%. It is worth noting that EmailLab’s internal Anti-spam Policy states that all mailings generating too many soft bounces (over 2%) and/or hard bounces (over 10%) may be quarantined, and the sender is required to explain if the exceeded percentage is only a one-time occurrence (e.g. sending rule changes to a less active base). We do not allow senders who regularly surpass the HB and SB critical values to continue sending out their campaigns. Monitoring the level of these statuses is crucial – the highest infrastructure reputation from each ISP ensures the highest quality of our service.

If you are experiencing problems with deliverability or want to know more about the statuses themselves, please contact our specialists who will be happy to provide you with any information you need.

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