Why are my emails blocked by Barracuda even when not listed on blocklists?

Email marketer from Reddit explains that spammers sometimes use open relays to send emails. If your server is misconfigured as an open relay, this can dramatically hurt your reputation and result in blocking by Barracuda.

Email marketer from Quora responds that high complaint rates (users marking emails as spam) can significantly damage sender reputation and lead to Barracuda blocking emails even without a formal blocklist entry. Focus on sending relevant emails to engaged subscribers.

Email marketer from Email Deliverability Forum responds that sudden large increases in email volume from a previously low-volume sender can trigger filters, including Barracuda, to block emails as a precaution, even without a specific blocklist entry. Gradual volume increases are recommended.

Email marketer from Reddit shares that Barracuda might be blocking emails due to a poor sender reputation, which is based on various factors like spam complaints, bounce rates, and engagement metrics, not just being on a blocklist.

Email marketer from StackOverflow shares that high bounce rates can negatively impact sender reputation and cause Barracuda to block emails even if the IP is not explicitly blocklisted. Maintaining a clean email list is important.

Email marketer from Email Geeks shares to check if the email got blocked before or after Barracuda clicked every link in the message, suggesting the content might be the cause.

Email marketer from SendGrid Support explains that if you're using a new dedicated IP address, Barracuda might block emails until the IP builds a positive sending reputation through a gradual warming process, even if the IP is not on any blocklists.

Email marketer from Email Marketing Tips Blog shares that poor list hygiene, including sending to old or invalid email addresses, can lead to increased bounce rates and spam complaints, which negatively affect sender reputation and result in blocking, even if not directly blocklisted.

Email marketer from Email Geeks suggests running an inbox test to see if Barracuda seeds exhibit the same blocking behavior.

Email marketer from Email Marketing Forum responds that certain keywords or phrases in the email content can trigger Barracuda's content filters, resulting in blocking, regardless of blocklist status. It is recommended to review the content and subject line for potential spam triggers.

Expert from Email Geeks suggests that the Barracuda block might be specific to a particular recipient.

Expert from Email Geeks advises sending a simple email without signatures or non-standard content to the recipient's system to test deliverability and identify potential blocking issues.

Expert from Spam Resource explains that Barracuda uses a variety of reputation factors beyond just blocklists to determine whether to block email. Even if you're not on a blocklist, a poor sender reputation based on factors like complaint rates or engagement metrics can still lead to blocking.

Expert from Word to the Wise explains that Barracuda blocks based on factors such as spam complaints. Ensure you clean your list and only mail engaged subscribers. Use tools to determine the reason for blocking.

Expert from Email Geeks recommends contacting the recipient through another channel to inquire if they received the email and to ask them to check their in-house Barracuda settings.

Documentation from Spamhaus explains that reputation systems like theirs feed into various filters, and even if not on a specific RBL (Realtime Blackhole List), a low reputation score can still cause blocking by systems like Barracuda.

Documentation from Cisco explains that senderbase.org provides reputation scores, and a low score might lead Barracuda to block emails even if the IP isn't on a direct blocklist. It recommends improving sending practices to improve the score.

Documentation from Barracuda Campus explains that even if an IP or domain isn't on a blocklist, Barracuda can still block emails based on content filtering, sender reputation (which includes factors beyond blocklists), and custom rules set by the recipient's organization.

Documentation from Barracuda Campus explains that their system uses 'intention analysis' to scan email content for phishing and scam characteristics. Even without specific keywords, a high score can result in blocking.

Documentation from Microsoft Learn explains that incorrect or missing SPF, DKIM, or DMARC records can cause Barracuda to flag emails as suspicious, leading to blocking, even if the sender isn't on a formal blocklist. These authentication methods help verify the sender's legitimacy.