Why are emails bouncing when sending to Tiscali.it and how to solve it?
Summary
What email marketers say13Marketer opinions
Email marketer from GlockApps shares that a good bounce rate should be below 2%. High bounce rates indicate problems with your email list or sending practices. Regular list cleaning and email validation are recommended.
Email marketer from SparkPost responds by describing that understanding the type of email bounce is important. They recommend parsing the SMTP response code to determine the cause of the bounce. Review the error codes to help identify the issue.
Marketer from Email Geeks explains that the first four MX servers are slow to respond, possibly causing timeouts if the MTA timeout is set too low.
Email marketer from Email Discussions explains that some bounces are due to DNS failures, resulting in temporary unavailability of the recipient's server. They suggests checking DNS settings and retrying.
Marketer from Email Geeks shares that Tiscali uses greylisting and has spotty response times. They suggest increasing wait times, adjusting connection timeouts, and reducing hourly throttles for Tiscali.
Email marketer from Neil Patel shares that maintaining a clean email list by removing inactive or bouncing email addresses is crucial for improving email deliverability. High bounce rates can negatively impact sender reputation.
Marketer from Email Geeks shares that Tiscali's low priority MX server sounds dead and provides MX records.
Email marketer from SendGrid explains that bounces can be hard or soft. A soft bounce is a temporary issue, like a full inbox or server problem, whereas a hard bounce indicates a permanent issue, such as an invalid email address. Only attempt to resend after soft bounces. Remove email addresses after hard bounces
Email marketer from Email Marketing Forum suggests contacting Tiscali.it's postmaster directly to inquire about the cause of the bounces and to request whitelisting, if possible. They also advise monitoring blacklists.
Email marketer from Mailradar responds by describing how greylisting can cause temporary bounces (4xx errors). Greylisting is used as an anti-spam measure. The solution is to retry sending later, as legitimate servers will retry.
Email marketer from Reddit shares that Tiscali.it is known for strict spam filtering and greylisting. They suggest warming up IPs gradually and ensuring proper email authentication (SPF, DKIM, DMARC).
Email marketer from MailPoet suggests troubleshooting bounce emails by checking for common issues, such as incorrect email addresses, full inboxes, or server problems on the recipient's side. They also recommend contacting the recipient to verify their email address is valid.
Email marketer from StackExchange shares that the error message smtp;421 4.2.1 Service not available means that the specific server you are trying to reach is unavailable. You can attempt to resend the email later.
What the experts say2Expert opinions
Expert from Word to the Wise responds by suggesting you check to see if you are on any blocklists. Many ISPs and corporations use blocklists to filter unwanted email. If you are on a blocklist, your emails could be rejected by the recipient's server. You will need to request removal from the blocklist.
Expert from Spam Resource explains that a bounce message should be examined to help determine the issues. A 4xx message usually means it is a temporary failure and you should retry later. A 5xx message indicates a permanent failure that might indicate the email address is incorrect.
What the documentation says5Technical articles
Documentation from Microsoft Support explains that the error “451 Temporary local problem - please try later” indicates a temporary issue with the recipient's server. Retrying the email delivery is recommended.
Documentation from Postfix.org explains that a 450 4.1.2 <recipient_address>: Recipient address rejected: Domain lookup failed, is caused by the mail server's inability to resolve the recipient domain. Ensure DNS servers are properly configured and can resolve external domains.
Documentation from RFC Editor details the status code 4.X.X. which indicates a temporary failure. The message should be resent at a later time.
Documentation from dkim.org explains how to set up DomainKeys Identified Mail (DKIM) to digitally sign your outbound email, which tells receiving mail servers that you authorized the message. You'll need access to your DNS records to do this.
Documentation from IETF explains that implementing DMARC (Domain-based Message Authentication, Reporting & Conformance) policy allows domain owners to protect their domain from unauthorized use, commonly known as email spoofing. It is built on top of SPF and DKIM to help mail receivers handle messages claiming to be from your domain.