Deliverability and sender reputation
Troubleshooting for Deliverability Problems
If the sending of your emails does not run smoothly, we talk about deliverability problems . These can take the form of bounces or spam delivery, or be visible through poor email KPIs such as low open and click rates.
Introduction to Deliverability
This section provides basic information and best practices for a successful deliverability. Email can be personalized, automated, tested, measured and more.
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.
Email content best practices
Creating good email content increases the general success of the ability to maintain good inbox placement. ISPs protect their users by using spam content filters, which work by analyzing a message before it is sent to the recipient’s inbox.
Sender reputation guide
Keeping your reputation is the most important part of sending emails. As a sender, you want to gain high performance and inbox placement.
CSA guidelines
Optimizely is a partner of the Certified Senders Alliance (CSA) and takes part in their allowlisting program, which complies with GDPR and ensures legal conformity of the sender's email marketing processes. CSA allowlisting offers preferred delivery and better inbox placement at participating Internet Service Providers.
IP warming
New sending IPs have no sending history and are considered a cold IP. At this point, they need to acquire a good reputation with ISPs.
Email authentication and encryption
Online abuse may occur in many ways, this includes spoofing of sender domains or email content and the sending of spam messages on behalf of someone else. To prevent this from happening, Optimizely applies a number of email authentication and encryption techniques.
Blocklists and blocklisting
An email blocklist is a real-time database, usually of an organization of the anti-spam community, that uses criteria to determine if an IP address or a domain is sending email that is considered to be spam and must therefore be prevented from further malicious activities. It helps the business using it to decide if emails received should be delivered to the final recipient or if they should rather be blocked because the sender is not trustworthy.
SMTP codes and error messages
This topic gives an introduction to the SMTP protocol and describes status codes and possible reasons for SMTP errors. SMTP stands for Simple Mail Transfer Protocol, which provides mechanisms for the transmission of emails and is the technical standard behind the sending, relaying and receiving of these.
DMARC implementation
DMARC stands for Domain-Based Message Authentication Reporting and Conformance (DMARC) and is a mechanism that is intended to counteract so-called email spoofing. Email spoofing is the sending of spam emails with fake domains, mostly on behalf of well-known companies and brands that are not even aware of this abuse.
List bombing: general information
Your newsletter registration process marks the beginning of your relationship with recipients. However, registration forms can be misused by malicious parties for sending spam through so-called list bombing attacks.
List bombing: protective measures
If you've identified a list bombing incident, multiple solutions are available. Determine when the attack began and review or remove all recipients (even DOI-confirmed) added after that time.
Deliverability glossary
This topic explains the most important terms related to deliverability.