Email deliverability remains a crucial aspect of successful digital marketing, ensuring that emails land in the intended recipient’s inbox rather than being filtered out or marked as spam. However, several technical issues can significantly hinder this process. Understanding and addressing these issues is key to maintaining effective communication and optimising email campaigns.
One of the most common technical problems affecting email deliverability is IP blacklisting. “If your sending IP address gets blacklisted by major blacklists like Spamhaus or Spamcop, your emails are likely to be blocked or classified as spam. To resolve this, it’s essential to first identify which blacklist(s) your IP is on,” Samarth Saxena, chief business officer, Sinch India, told BrandWagon Online. Free online tools can assist in this process. Once identified, follow the removal process outlined by the blacklist provider, which usually involves addressing the root cause, such as reducing spam complaints, Saxena added. Regular monitoring and adherence to good sending practices can help prevent future blacklisting. In cases where the blacklisting is mistaken, directly contacting the blacklist provider to request removal can also be effective.
“Throttling which may involve the control of the amount of traffic coming from untrusted senders is also a drawback,” Faraz Alam, founder, Tole Lifestyle, said. Another significant issue is encountering spam traps—email addresses specifically used to catch spammers. Hitting a spam trap can severely damage your sender’s reputation and affect deliverability. “To avoid getting into spam traps, always clean your lists, use double opt-in lists and never use purchased lists. Put in place of proper bounce handling to delete poor lists fast at regular intervals,” Alam said. Further, practices such as SPF, DKIM, and DMARC that authenticate your emails considerably can do a lot to rebuild your sender’s reputation in the long run, he highlighted. Furthermore, implementing double opt-in procedures and regularly cleaning your list to remove inactive or suspicious addresses is crucial. Additionally, monitoring feedback loops and spam trap data can provide insights into potential issues and help rectify them.
The content and design of your emails also play a critical role in determining deliverability rates. Emails that offer high-quality, relevant content are more likely to engage recipients, thus improving deliverability. “Avoiding spam language, excessive links, and large attachments helps maintain good deliverability. Furthermore, well-designed and properly formatted emails—those that are mobile-friendly, use clean HTML code, and avoid broken links or excessive images—are less likely to be flagged by spam filters,” Saxena added. Incorporating Accelerated Mobile Pages (AMP) can further enhance the user experience by providing real-time updates and interactive features directly within the email, reducing the need for recipients to navigate away.
Internet Service Providers (ISPs) and spam filters utilise various techniques to decide whether an email should be delivered or blocked. Spam filters evaluate emails for characteristics associated with spam using algorithms and machine learning. Reputation systems are also employed, where ISPs assess past behaviours, such as spam complaints and bounce rates, to gauge sender reputation and delivery likelihood.
Authentication checks are crucial as well; emails failing SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), or DMARC (Domain-based Message Authentication, Reporting & Conformance) are more likely to be flagged or blocked. “Messages from high-reputation senders with correct authentication parameters are the ones to be delivered by the recipient’s email server. Filters also search for any prohibited content which includes spam content and links, unattractive looks and too many links in the content,” Alam said. Additionally, engagement metrics play a role; high recipient engagement, including opens and clicks, can improve deliverability, whereas low engagement or frequent deletions can negatively impact it.
Other factors also include engagement which is a measure of how often the recipients open, click, or mark your emails as spam. “Constantly improving things that comprise those areas increases the credibility of the emails among the ISPs,” Saxena said.