What are the best practices for sending email to Polish providers like Interia to avoid throttling?

Summary

To achieve optimal email deliverability to Polish providers like Interia and minimize throttling, a multifaceted approach is essential. Start by establishing a good sender reputation, which involves adhering to volume limits (beginning around 1,000 messages per day and incrementally increasing by 12% every 2-3 days, monitoring for blocks), proper email authentication (SPF, DKIM, and DMARC), and maintaining a clean and engaged email list. Be aware of potential pay-to-play models with Polish providers. Monitor your sender reputation through tools like Postmaster Tools, avoid spam triggers in your email content, and ensure you have explicit consent from recipients. Warm up new IP addresses gradually, segment your email lists for more targeted sends, and proactively check for blacklisting. Consider that European providers often throttle more aggressively, so domain alignment and adherence to their specific guidelines are crucial. Finally, implement feedback loops and regularly review sending practices to adapt to changing ISP requirements.

Key findings

  • Volume Management: Gradual volume increase is key; starting low (around 1,000 emails/day) and increasing by 12% every 2-3 days, while monitoring for blocks.
  • Authentication is Crucial: SPF, DKIM, and DMARC are non-negotiable for verifying sender legitimacy and preventing spoofing.
  • Sender Reputation Matters: ISPs heavily rely on sender reputation to determine deliverability; a poor reputation will lead to throttling or blocking.
  • List Hygiene is Essential: Regularly cleaning your email list to remove inactive or invalid addresses minimizes bounce rates and improves deliverability.
  • European ISPs are Strict: European ISPs often have stricter throttling policies, so domain alignment (CNAMEs), authentication, and monitoring are even more critical.

Key considerations

  • Pay-to-Play Models: Be aware of the potential for pay-to-play models with Polish providers, as these can impact deliverability and may require budget allocation.
  • IP Warm-Up: If using new IP addresses, warm them up gradually to establish a positive sender reputation.
  • Segmented Sending: Segment your lists to target specific audiences and send relevant content, improving engagement and reducing spam complaints.
  • Avoid Spam Triggers: Carefully craft email content to avoid spam trigger words and phrases that can lead to filtering.
  • Monitor Blacklists: Regularly check your IP address and domain against blacklists to identify and address any reputation issues promptly.
  • Get Consent: Ensure you have explicit consent from recipients before sending emails to comply with regulations and improve engagement.
  • Feedback Loops: Implement feedback loops to monitor complaints and improve sending practices.
  • Monitor Performance: Continuously monitor email performance and adjust your strategies accordingly.

What email marketers say
11Marketer opinions

To effectively send emails to Polish providers like Interia and avoid throttling, it's crucial to manage your sending reputation and adhere to specific volume guidelines. Starting with a low volume of around 1,000 messages per day and gradually increasing by 12% every 2-3 days is advised. Authentication (SPF, DKIM, DMARC) is vital, as is list hygiene, and monitoring your sender reputation. Additionally, Polish providers may have a pay-to-play model. Warming up your IP address, segmenting your lists, avoiding spam trigger words, and ensuring recipients add you to their address book are also important.

Key opinions

  • Volume limits: Start with low sending volumes (around 1,000 messages/day) and increase gradually to avoid triggering throttling mechanisms.
  • Authentication: Properly authenticate your emails using SPF, DKIM, and DMARC to prove your legitimacy to email providers.
  • Pay-to-play: Be aware that some Polish providers may have a pay-to-play model that can impact deliverability.
  • Segmentation: Segment your email lists to send more targeted and relevant content to smaller groups of recipients, improving engagement.
  • Sender Reputation: Focus on improving and maintaining sender reputation with ISPs, as this will severely affect your email deliverability.

Key considerations

  • IP Warmup: If using a new IP address, gradually warm it up by increasing sending volume over time to establish a positive reputation.
  • List Hygiene: Regularly clean your email lists to remove invalid or inactive addresses, reducing bounce rates and improving engagement.
  • Blacklist Monitoring: Monitor your IP address and domain for blacklisting to address any reputation issues promptly.
  • Content Quality: Avoid using spam trigger words and create valuable, engaging content that encourages recipients to add you to their address book.
  • Consent: Ensure that you have explicit consent from recipients before sending emails, reducing the risk of spam complaints.
  • Provider Guidelines: Research and understand specific guidelines from Polish providers like Interia, as European providers tend to throttle more aggressively and prefer authentication/domain alignment
Marketer view

Email marketer from MailerCheck explains that email throttling is a process by which a mail service provider (MSP) like Gmail, Outlook, or Yahoo! intentionally slows down the rate at which it accepts email from a particular sender. They recommend improving sender reputation, using dedicated IP address and warming it up, authenticating email and cleaning email list.

August 2024 - MailerCheck
Marketer view

Email marketer from Omnisend notes that, when sending emails, ISPs and email providers scan them for spam triggers to determine if they should deliver the message, filter it, or reject it altogether. They suggest cleaning your email lists, getting consent, writing a great subject line and properly authenticating to avoid spam filters.

March 2024 - Omnisend
Marketer view

Email marketer from SparkPost shares that good email deliverability means that your messages are landing in your recipients' inboxes and not in the spam folder. They recommend authenticating your email, cleaning your list, segmenting your audience, monitoring your reputation, and providing value.

October 2022 - SparkPost
Marketer view

Email marketer from Reddit shares that one thing you could try is looking into DKIM. It can help prove to mail providers that you are who you say you are. It will require DNS access to set up properly

December 2023 - Reddit
Marketer view

Email marketer from Reddit notes that blacklists are lists of IP addresses and domains that have been identified as sources of spam. If you are on a blacklist, your emails may be blocked or sent to the spam folder. They recommend checking your IP address and domain against known blacklists. They also share that there are paid services to automatically monitor this.

July 2024 - Reddit
Marketer view

Marketer from Email Geeks shares that they've been told to start at 1,000 messages per day in Poland for any MBP, then increase volume 12% every 2-3 days. If the MBP blocks, do not increase volume; reduce volume and wait until blocking stops.

November 2022 - Email Geeks
Marketer view

Email marketer from SenderGuardian shares that warming up an IP address involves gradually increasing the volume of email sent from that IP over a period of time. This helps to establish a positive sender reputation with ISPs. SenderGuardian suggest starting with low volumes and gradually increasing the number of emails sent each day.

May 2024 - SenderGuardian
Marketer view

Email marketer from Litmus explains to avoid spam filters by avoiding spam trigger words, having good IP reputation, getting recipients to add you to their address book and have good authentication. It is also good to have a dedicated IP and domain.

July 2023 - Litmus
Marketer view

Email marketers from Email Geeks discuss Interia throttling. Nick is experiencing general throttling for 2k minutes and support hasn't responded. Patrick suggests considering volume limits, authentication, and specific bounce messages, and that volume may be playing a role due to shared IPs. Nick states he has tried requesting delistings with no impact. They both agree the volume isn't excessive. Nick notes that polish providers have a pay to play model, including a certification program. Patrick adds European providers tend to throttle more aggressively and prefer authentication/domain alignment, suggesting CNAMES for return path domains. Nick adds the mail engineers have not done any specific testing.

October 2021 - Email Geeks
Marketer view

Email marketer from EmailVendorSelection.com answers that throttling is when an ISP temporarily blocks emails from a specific source (IP or domain) that exceed certain volume limits or have a poor sender reputation. To avoid it, they recommend warming up your IP address, segmenting your list, and monitoring your sending reputation.

July 2021 - EmailVendorSelection.com
Marketer view

Email marketer from GMass explains that email deliverability refers to your ability to successfully deliver emails to your subscribers’ inboxes. To improve deliverability, they suggest authenticating your email, cleaning your list, warming up your IP address, monitoring your reputation, and segmenting your audience.

April 2021 - GMass

What the experts say
2Expert opinions

Maintaining a positive sender reputation is critical for avoiding email throttling by Polish providers like Interia. Throttling occurs when ISPs delay or refuse messages due to suspected spam-like activity or high volume. Experts recommend authentication, list segmentation, content creation, and volume monitoring to maintain a good sender reputation.

Key opinions

  • Sender Reputation: A poor sender reputation significantly impacts email deliverability, leading to throttling and potential blocking of messages.
  • Throttling Triggers: ISPs throttle emails based on perceived spam-like behavior, which includes high sending volume or content that triggers spam filters.
  • Proactive Measures: Implementing best practices in authentication, list hygiene, and content creation can improve sender reputation and prevent throttling.

Key considerations

  • Authentication: Ensure proper email authentication methods are in place (SPF, DKIM, DMARC) to verify the legitimacy of your messages.
  • List Segmentation: Segment email lists to send targeted and relevant content to specific groups, reducing the likelihood of spam complaints.
  • Content Quality: Create high-quality, engaging content that avoids spam trigger words and provides value to recipients.
  • Volume Monitoring: Monitor email sending volumes and adjust as necessary to avoid exceeding the thresholds set by ISPs.
Expert view

Expert from Spamresource explains the importance of sender reputation when sending emails. They note that having a poor sender reputation will severely affect your email deliverability. They recommend implementing best practices in authentication, list hygiene, and content creation.

May 2023 - Spamresource
Expert view

Expert from Word to the Wise explains that throttling happens when an ISP temporarily delays or refuses to accept messages from an IP or domain. This is often due to perceived spam-like behavior or high volume. They recommend maintaining a good sending reputation by authenticating, segmenting lists, and monitoring volume.

June 2023 - Word to the Wise

What the documentation says
4Technical articles

To ensure email deliverability, especially with providers like Gmail and, by extension, Polish providers using similar protocols, it's crucial to implement robust authentication methods (SPF, DKIM, and DMARC). SPF allows domain owners to specify authorized mail servers, DKIM signs messages for verification, and DMARC dictates how receivers should handle authentication failures while providing reporting. Maintaining consistent sending volumes, avoiding unwanted mail, and monitoring sender reputation using tools like Postmaster Tools are also essential. For marketing emails, including a List-Unsubscribe header is a best practice.

Key findings

  • Authentication Importance: SPF, DKIM, and DMARC are critical for authenticating emails, ensuring they are delivered and not marked as spam.
  • Sender Policy Framework (SPF): SPF records allow domain owners to specify authorized mail servers, enabling receivers to verify the email's origin.
  • DomainKeys Identified Mail (DKIM): DKIM provides a digital signature that verifies the message's integrity and authenticity.
  • DMARC Enforcement: DMARC builds on SPF and DKIM by instructing receivers on how to handle authentication failures and providing reporting mechanisms.
  • Volume Consistency: Maintaining consistent sending volumes helps establish trust with email providers and reduces the likelihood of throttling or spam classification.

Key considerations

  • SPF Record Setup: Accurately configure SPF records to list all authorized sending IP addresses and domains.
  • DKIM Key Management: Properly generate, store, and manage DKIM private keys, ensuring they are securely implemented on sending servers.
  • DMARC Policy Configuration: Carefully configure DMARC policies to dictate how receivers handle authentication failures (e.g., reject, quarantine) and set up reporting to monitor results.
  • Gmail Guidelines: Follow Gmail's sender guidelines, including sending wanted mail and providing a List-Unsubscribe header for marketing emails.
  • Reputation Monitoring: Use tools like Gmail's Postmaster Tools to monitor your sender reputation and address any deliverability issues proactively.
Technical article

Documentation from RFC-Editor explains that DMARC (Domain-based Message Authentication, Reporting & Conformance) builds upon SPF and DKIM to provide a way for domain owners to specify how receiving mail servers should handle messages that fail authentication checks. DMARC also provides a reporting mechanism that allows domain owners to receive feedback about authentication results.

January 2022 - RFC-Editor
Technical article

Documentation from Gmail Help explains that to ensure Gmail delivers your messages, authenticate your email with SPF, DKIM, and DMARC. Send consistent volume. Avoid sending unwanted mail. Monitor your sender reputation in Postmaster Tools. Follow Gmail's sender guidelines. If you send marketing emails, use the List-Unsubscribe header.

April 2023 - Gmail Help
Technical article

Documentation from RFC-Editor explains DomainKeys Identified Mail (DKIM) provides a way to authenticate email messages by digitally signing them with a private key. Receiving mail servers can then verify the signature using the public key published in the domain's DNS record. DKIM helps to ensure that the message has not been altered in transit and that it is coming from an authorized source.

June 2023 - RFC-Editor
Technical article

Documentation from RFC-Editor explains Sender Policy Framework (SPF) allows domain owners to specify which mail servers are permitted to send email on behalf of their domain. The SPF record contains a list of authorized IP addresses or domain names. Receiving mail servers can then verify the SPF record to ensure that incoming mail from the domain is coming from an authorized source.

January 2022 - RFC-Editor