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Deliverability of Emails

Just sending an email does not mean that the email will reach its destination. Practice shows that many emails are accepted, but do not arrive in the recipient's inbox.

It can also be observed that not infrequently 1 % or in some cases even more of all emails sent are simply lost on the way to the recipient.

Email delivery or deliverability?

It is important to differentiate what is the difference between email delivery and deliverability – especially for professional email senders, the deliverability is very important for the highest possible ROI.

What is email delivery?

Delivery is about the email being accepted by the responsible mail server. This step comes before the email can actually be delivered to the mailbox or one of the recipient's subfolders.

If an email is rejected by the receiving server, the delivery of the email was unsuccessful and, accordingly, the email cannot be delivered to the recipient's mailbox.

What is email deliverability?

Deliverability is about getting the email in the recipient's inbox in the best case. The email has been accepted and will then be placed in one of the folders in the recipient's email mailbox.

So the first step is to get an email accepted. You don't always have an influence on whether an email will be accepted or rejected.

An email can be rejected, for example, for one of the following reasons:

  • the recipient has deleted his email address.
  • the recipient address has been deactivated.
  • the recipient's mailbox is full and there is no space for new emails.
  • the sender has a bad reputation or a technical error and his emails are therefore rejected when they arrive.

If an email is accepted, it will be delivered afterwards and the delivery was successful.

In the next step, we are interested in the deliverability. The better the deliverability, the more recipients will be able to quickly find and read an email in the mailbox.

If the deliverability is good, many emails are stored in the recipient's main mailbox after delivery. On the other hand, if it is bad, many emails end up in the spam folder or another subfolder, where they are easily overlooked.

A high deliverability depends on many factors, the following are very important:

  • Technology – Emails must be sent with mail servers that are technically flawlessly set up and in which all important identification methods such as SPF, DKIM, and DMARC are correctly implemented.
  • Reputation – every email sender has a reputation. Among other things, the reputation is firmly linked to the IP address and the host name of the email dispatch server. Reputation can be actively influenced by sending legitimate emails and having a clean recipient list.
  • Content and subject – the content and subject of the email can also have a major impact on the deliverability. If either the content or subject is suspicious while going through the spam filter, the deliverability of the email will be poor.

When testing the email marketing providers, the most important thing for us is the deliverability of the emails.

In most cases, delivery is not a problem. In terms of the deliverability, on the other hand, many providers of corresponding services have the greatest difficulties, as our tests show.

Learn more about how we test email deliverability