Why are emails bouncing when sending to Tiscali.it and how to solve it?

Summary

Emails to Tiscali.it bounce due to a combination of factors: Tiscali's slow or unresponsive mail servers and greylisting, strict spam filtering, DNS failures, temporary server unavailability, and sender-side issues. Solutions encompass retrying, adjusting timeouts, cleaning lists, warming IPs, proper authentication (SPF, DKIM, DMARC), contacting Tiscali, monitoring blocklists, examining bounce messages, and ensuring DNS is configured correctly.

Key findings

  • Tiscali Server Issues: Slow or dead MX servers and greylisting impact deliverability.
  • Strict Filtering: Tiscali's stringent spam filters require a good sender reputation.
  • DNS Problems: Domain Name System resolution failures lead to bounces.
  • Bounce Analysis: Analyzing bounce codes (4xx vs 5xx) reveals temporary vs permanent issues.
  • Authentication Importance: SPF, DKIM, and DMARC are crucial for verifying sender identity and trustworthiness.
  • List Hygiene: Maintaining a clean email list reduces bounce rates.

Key considerations

  • Retry Soft Bounces: Resend emails that result in soft bounces.
  • Adjust Timeouts: Increase wait times and connection timeouts to accommodate Tiscali's servers.
  • Clean Your List: Remove inactive and bouncing email addresses to boost sender reputation.
  • Warm-Up IPs: Increase the sending volume gradually to establish a positive sender reputation.
  • Implement Authentication: Ensure proper SPF, DKIM, and DMARC setup to authenticate emails.
  • Contact Tiscali: Contact Tiscali's postmaster for whitelisting or more information.
  • Monitor Blocklists: Check for and remove your IPs from blocklists.
  • Check DNS Configuration: Ensure DNS servers are correctly configured and can resolve external domains.
  • Validate Email Addresses: Validate email addresses to minimize hard bounces.

What email marketers say
13Marketer opinions

Emails to Tiscali.it may bounce due to a combination of factors, including issues with Tiscali's mail servers (slow or dead MX records), greylisting, strict spam filtering, DNS failures, and temporary server unavailability. Solutions involve retrying, adjusting timeout settings, cleaning your email list, warming up IPs, implementing proper email authentication (SPF, DKIM, DMARC), contacting Tiscali's postmaster, and monitoring blocklists.

Key opinions

  • MX Record Issues: Tiscali's MX records may be slow to respond or even non-responsive, causing connection timeouts.
  • Greylisting: Tiscali employs greylisting, which causes temporary bounces; legitimate servers should retry delivery.
  • Strict Spam Filtering: Tiscali has strict spam filters, requiring a strong sender reputation and proper authentication.
  • DNS Failures: Temporary bounces can result from DNS resolution problems on the recipient's server.
  • Bounce Types: Understanding the difference between soft and hard bounces is important for list management.

Key considerations

  • Retry Sending: For temporary failures (soft bounces), retry sending the email.
  • Adjust Timeout Settings: Increase wait times and adjust connection timeouts to accommodate Tiscali's slower servers.
  • Clean Email List: Remove inactive or bouncing email addresses to improve sender reputation.
  • Warm Up IPs: Gradually increase sending volume to Tiscali to establish a positive sending reputation.
  • Implement Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) to verify sender legitimacy.
  • Contact Tiscali Postmaster: Reach out to Tiscali's postmaster for assistance and potential whitelisting.
  • Monitor Blocklists: Check if your sending IPs are on any blocklists and take steps to remove them.
  • SMTP Error codes: Review error codes to help identify the issue.
Marketer view

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.

July 2024 - GlockApps
Marketer view

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.

December 2024 - SparkPost
Marketer view

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.

July 2024 - Email Geeks
Marketer view

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.

February 2025 - Email Discussions
Marketer view

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.

March 2025 - Email Geeks
Marketer view

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.

July 2023 - Neil Patel
Marketer view

Marketer from Email Geeks shares that Tiscali's low priority MX server sounds dead and provides MX records.

April 2022 - Email Geeks
Marketer view

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

June 2022 - SendGrid
Marketer view

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.

April 2023 - Email Marketing Forum
Marketer view

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.

December 2021 - Mailradar
Marketer view

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).

April 2024 - Reddit
Marketer view

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.

May 2023 - MailPoet
Marketer view

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.

January 2022 - StackExchange

What the experts say
2Expert opinions

When emails bounce, especially to Tiscali.it, it's essential to analyze the bounce messages. A 4xx error typically signifies a temporary issue requiring a retry, while a 5xx error indicates a permanent failure, possibly an incorrect email address. Additionally, it's crucial to verify if your sending IP or domain is blocklisted, as this can lead to email rejections; if blocklisted, initiate the removal process.

Key opinions

  • Bounce Message Analysis: Analyzing bounce messages (4xx vs. 5xx errors) is crucial for identifying the nature of the delivery problem.
  • Blocklist Status: Being on a blocklist can cause email rejections by the recipient's server.

Key considerations

  • Retry on Temporary Failures: If the bounce message indicates a temporary failure (4xx error), retry sending the email.
  • Verify Email Address: If the bounce message indicates a permanent failure (5xx error), verify the recipient's email address for accuracy.
  • Check Blocklist Status: Regularly check if your sending IP/domain is on any blocklists.
  • Initiate Blocklist Removal: If blocklisted, promptly initiate the removal process according to the blocklist's procedures.
Expert view

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.

February 2022 - Word to the Wise
Expert view

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.

April 2023 - Spam Resource

What the documentation says
5Technical articles

Emails bounce when sending to Tiscali.it for several technical reasons, including DNS lookup failures, temporary server issues, and lack of proper email authentication. Solutions involve ensuring correct DNS configuration, retrying delivery for temporary errors, and implementing DMARC and DKIM for enhanced security and sender verification.

Key findings

  • DNS Lookup Failures: Mail servers may fail to resolve the recipient domain, leading to bounce messages.
  • Temporary Server Issues: Temporary local problems on the recipient's server can cause transient delivery failures.
  • Temporary Failures: 4.X.X status codes indicate temporary issues that warrant retrying the email.
  • Email Spoofing Protection: DMARC protects against unauthorized use and email spoofing.
  • DKIM Implementation: DKIM digitally signs outbound emails, verifying authorization to receiving mail servers.

Key considerations

  • Verify DNS Configuration: Ensure DNS servers are correctly configured and can resolve external domains.
  • Retry Delivery: Retry sending emails that resulted in temporary errors (4.X.X codes).
  • Implement DMARC: Implement DMARC to protect against email spoofing by adding a DMARC record to the DNS zone.
  • Set Up DKIM: Set up DKIM signing for outbound emails using access to DNS records, this improves deliverability by helping mail servers verify that authorized mail servers are sending the emails.
Technical article

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.

July 2024 - Microsoft
Technical article

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.

May 2022 - Postfix.org
Technical article

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.

January 2023 - RFC Editor
Technical article

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.

September 2023 - dkim.org
Technical article

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.

June 2023 - ietf.org