Deliverability best practices

Good deliverability is no coincidence. High delivery and open rates are mainly a result of the general email marketing strategy and the associated adherence to industry best practices. After all, what is the point of fancy features if the email is not delivered and the recipient never sees it? The following is an overview of best practices as represented by internet service providers (ISPs) and valid in the email sector.

Clean contact acquisition process

Use contacts who actively signed up to receive your promotional mailings. This is legally required and provides the best delivery rates, as you would expect the best user engagement from them.

Avoid recipient sources such as purchased lists, lead generation, or affiliate marketing partners, as the quality of contacts is often poor, legally non-compliant, and negatively impacted by lack of concrete opt-ins and questionable acquisition methods.

Clear expectations from the beginning

• At the time of collecting his email address, is the recipient aware of what kind of commercial emails you will send?
• Lack of clarity can lead to poor open rates and spam complaints.
• Let the recipient actively manage preferences and desired frequency, for example by means of a preference center.

Double opt-In

A double opt-in A practice in which a recipient consents to receiving email from the sender before any promotional email is sent. Recipients receive an email with a double opt-in link, which they must click to confirm their interest. process is the only way to protect your database from unauthorized third-party registrations, as recipients are actively verified by clicking the activation link in their email account. Spam traps can be prevented from being introduced into the database as no confirmation click is expected from them. Storage and documentation of the complete registration data as required by the GDPR Stands for "General Data Protection Regulation" legislation can only be guaranteed by a double opt-in process.

For more information on the double opt-in process and how to implement it with Optimizely Campaign, see Opt-in.

Registration forms with Captcha

Captcha is the best way to protect your registration forms against misuse. Especially in the age of bot and list bombing attacks, it has become indispensable. Integrating a Captcha protects your database from malicious addresses and the systems involved against DDOS attacks.

Your recipients attach great importance to data protection and will understand this as a confidence-building security measure.

User-friendly unsubscription process

An easy-to-find unsubscribe link should be present in every commercial email. A recipient's opt-out request of should be respected. You should allow the unsubscription from any marketing communication through a maximum of two clicks: on the link itself and, if necessary, a second time in a preference center.

Refrain from requesting additional logins or sending unsubscribe confirmation emails, as these may lead to frustration and spam complaints.

List hygiene

• Each contact should be sent to at least once every 6 months to sustainably clean up the database and avoid a high number of hard bounces Hard bounces occur when an email cannot be delivered due to a permanent error (for example because the email address no longer exists)..
• Exclude recipients who were not active in the newsletter in the last 12 months from regular mailings. These email accounts might be converted into spam traps by the ISPs after that amount of time.
• Legacy data often results in low open rates and, related to that, a loss of good deliverability performance.

Focus on engaged recipients

Your email marketing activities should focus on your active recipients because they are responsible for good open and delivery rates, and also form the basis of your revenue generation. These include contacts who were recently active in your emails, on your website and other channels; recipients who opened and clicked several times; and users who browsed your website and bought products from your shop. Only they should receive email from you regularly.

Exclude and reactivate inactive users

Exclude from the regular newsletter contacts who do not open for a long period of time. Lack of feedback leads ISPs to believe that your emails are uninteresting or even unintentional to the major part of your recipients, and they may punish you with spam folder delivery.

Inactive recipients, however, may occasionally be sent to with winback campaigns.

Relevant content through segmentation and personalization

• Take advantage of Optimizely Campaign's segment A term for dividing recipients into relevant groups to send them appropriate content. Optimizely Campaign uses Target Groups and Click Profiles for segmentation. feature and work with as many target groups Subset of recipients defined by rules and conditions and a logic relationship between them. For example, all recipients in the United Kingdom. as possible.
• You can generally apply filtering to many areas, such as user engagement, regions, interests, purchased products and age groups.
• Do not only send the same mailings exclusively to the complete database. Variation leads to more relevant content and thus better email performance KPIs Stands for "key performance indicator" (also known as a conversion goal); the measurement of actions on web pages. The actions can be completed purchases, pages visited, time spent on site and so on..
• Irrelevant content causes poor open rates, unsubscriptions, and spam complaints in the long term.

Transparent mailing content

Your emails aim to build a relationship of trust with your brand. Therefore, they should contain an unsubscribe link, a link to the privacy policy, and a full legal imprint.

Email content should look trustworthy not only to the recipient but also to the ISP and its spam filter. Therefore, make sure your emails are not empty, do not contain any phishing-like links, and that you have an appropriate HTML / text ratio and identical HTML and text versions.

Adequate frequency

Adjust the sending frequency to your business model, but do not overwhelm your recipients. Bombarding recipients with emails can lead to high levels of spam complaints, unsubscriptions, and public complaints in anti-spam forums, which have a negative impact on your sender reputation and deliverability.

Be clear about how often your newsletter will be sent, comply with it, and give your recipients the opportunity to adjust frequency according to their needs.

Stable sending volume

Heavily changing sending volume is a typical characteristic of spammers. Since the emails of ordinary senders might be also misclassified in such cases, avoid large irregularities of the volume sent. If you need to send much larger quantities of emails due to seasonal requirements, a slow and steady increase is recommended.