Why are my emails bouncing and is my sending IP on the SORBS spam blocklist?
Summary
What email marketers say12Marketer opinions
Email marketer from Gmass shares that gradually warming up a new IP address is crucial. Start with a small volume of emails and gradually increase it over time to build a positive sending reputation.
Email marketer from SendPulse shares that you can check if your IP address is on a blocklist using online tools like MultiRBL. These tools query various blocklists and report if your IP is listed on any of them.
Email marketer from Mailjet explains that email bounces occur when an email cannot be delivered to the recipient. Hard bounces indicate a permanent reason, such as a non-existent email address, while soft bounces are temporary issues like a full inbox or server problems.
Email marketer from Email Geeks shares from experience that if bouncing due to an RBL listing, the RBL is usually mentioned in the bounce message.
Email marketer from Reddit explains that some common reasons for bounces include invalid email addresses, spam filters, and server issues. They recommend regularly cleaning your email list and monitoring bounce rates.
Email marketer from MailerQ explains that subscribing to feedback loops (FBLs) allows you to receive reports when recipients mark your emails as spam. This helps you identify and address potential issues with your sending practices.
Email marketer from Quora explains that if you are using a shared IP address, the sending behavior of other users can affect your deliverability. If another user is sending spam, it can negatively impact your IP's reputation and lead to bounces.
Email marketer from StackExchange shares that if your IP is on SORBS, it's essential to investigate the cause. They suggest contacting SORBS to understand why you were listed and what steps you need to take to be removed.
Email marketer from Superuser forum suggests ensuring you have a properly configured reverse DNS (PTR) record. A matching PTR record can help improve your sender reputation and reduce the likelihood of being flagged as spam.
Email marketer from Litmus shares that improving email deliverability involves several steps, including authenticating your email with SPF, DKIM, and DMARC; maintaining a clean email list; and monitoring your sender reputation.
Email marketer from Email Geeks reinforces that while SORBS may not be widely used, a listing there often indicates other sending issues.
Email marketer from GlockApps explains that being on a blocklist can significantly impact email deliverability, causing emails to be rejected or sent to the spam folder. This can damage sender reputation and reduce engagement.
What the experts say6Expert opinions
Expert from Email Geeks notes if you're on shared IPs, the blocking issue may be someone else's fault.
Expert from Email Geeks shares the common sequence of events where mail bounces, someone looks up the IP on a lookup site, and panics about the RBL instead of finding the actual cause.
Expert from Spamresource details steps to determine if you have been blacklisted on an email blacklist, and if so, provides links to lookup your IP reputation with each of the major block list organisations.
Expert from Email Geeks explains that SORBS is not widely used to block mail, but a SORBS listing often correlates with other issues that cause blocking elsewhere.
Expert from Word to the Wise explains that while SORBS itself might not be a primary blocklist for major ISPs, being listed on it can be an indicator of underlying issues with your sending practices, leading to deliverability problems elsewhere. She suggests focusing on overall email best practices.
Expert from Email Geeks explains that if sending through SFMC, they are not blocking the mail but can provide the rejection messages indicating who is blocking and why.
What the documentation says4Technical articles
Documentation from RFC-Editor explains that Sender Policy Framework (SPF) records specify which mail servers are authorized to send email on behalf of your domain. This helps prevent spoofing and improves deliverability.
Documentation from DKIM.org explains that DomainKeys Identified Mail (DKIM) is an email authentication method that uses a digital signature to verify the sender's identity. Implementing DKIM can improve deliverability and prevent spoofing.
Documentation from Spamhaus explains that SORBS (Spam and Open Relay Blocking System) is a DNSBL (DNS-based Blackhole List) that lists IP addresses of computers or networks which are sources of spam. Being listed on SORBS can lead to email delivery problems.
Documentation from Microsoft explains that bounce messages, also known as Non-Delivery Reports (NDRs), contain information about why an email was not delivered. Examining the NDR can help identify the specific reason for the bounce, such as a blocked IP or a non-existent recipient.