What does the 'Abus detecte GU_EIB_04' error from SFR.fr mean for email deliverability and how to address it?
Matthew Whittaker
Co-founder & CTO, Suped
Published 18 Apr 2025
Updated 19 Aug 2025
6 min read
Encountering the 'Abus detecte GU_EIB_04' error from SFR.fr can be quite concerning for anyone managing email campaigns or transactional sends. This particular bounce code signals a significant issue: SFR.fr's systems have identified your messages as undesirable, leading to a temporary block (or blocklist, also known as a blacklist).
When you see this error, it means your emails are not reaching their intended recipients at SFR.fr, directly impacting your email deliverability. It is essentially an indication that SFR, a major French internet service provider, has flagged your sending behavior or content as suspicious.
Addressing this error promptly is vital. Ignoring it can lead to longer blocking periods and more severe damage to your sender reputation, affecting all future email communications with SFR.fr users and potentially other ISPs as well. Let's delve into what this error truly means and how you can tackle it head-on.
Understanding the 'Abus detecte GU_EIB_04' error
The 'Abus detecte GU_EIB_04' error code from SFR.fr typically indicates that your email has been classified as spam by their filtering systems. This classification isn't arbitrary, it is based on various factors, including recipient complaints, sender reputation, and content analysis.
SFR.fr, like many ISPs, uses sophisticated anti-spam technologies. A key player in their defense is VadeSecure. VadeSecure's systems are known for their sensitive detection of spam-like patterns. This means even a small number of complaints or slightly off-kilter sending behavior can trigger this block.
While the block itself is temporary, repeated occurrences without addressing the underlying issues can lead to more persistent blocking. It signals that your domain or IP address is currently not trusted by SFR.fr, preventing your legitimate emails from reaching inboxes. It's a clear indicator that your email deliverability for French domains is suffering.
Temporary vs. permanent blocking
Initially, the GU_EIB_04 error often results in a short-term block. However, if your sending practices do not improve and you continue to trigger the error, SFR.fr will extend the duration of these blocks, potentially leading to a long-term or even permanent blacklisting of your IP or domain.
The key is to act quickly. Ignoring these signals is one of the reasons emails fail. Repeated attempts to send mail while blacklisted can reinforce the negative perception and make recovery much harder.
Common causes of the SFR.fr blocklist
The primary cause for the GU_EIB_04 error is a high complaint rate. When recipients mark your emails as spam, SFR.fr takes note. Even a seemingly small number of complaints can trigger this block, especially if you are sending low volumes of email.
Beyond explicit complaints, low engagement metrics (such as low open and click rates) can also contribute. ISPs interpret disengagement as a sign that your emails might not be wanted, leading them to filter your messages into the spam folder or reject them outright. Sending to old, uncleaned lists that contain inactive or invalid email addresses also plays a significant role.
Sometimes, the issue isn't solely your sending practices. SFR.fr's reliance on VadeSecure, for instance, can lead to false positives. If you send only a couple of emails and one generates a complaint, VadeSecure might register an alarmingly high complaint rate (e.g., 50%), triggering the block. This highlights the sensitivity of their filtering system, as noted on the SFR Postmastery page.
Sender behavior issues
High complaint rates: Recipients marking your emails as spam due to unsolicited content or frequency.
Low engagement: Lack of opens, clicks, or replies indicating recipients are not interested in your content.
Poor list hygiene: Sending to outdated, purchased, or unengaged email lists.
Content issues: Spammy keywords, broken links, or suspicious formatting.
Shared IP blocks: Negative reputation from other senders on a shared IP (if not using dedicated IPs).
Steps to resolve the error and restore deliverability
The first and most crucial step when you encounter the 'Abus detecte GU_EIB_04' error is to pause all email sends to SFR.fr recipients. Continuing to send while blacklisted will only worsen the situation and prolong the block. This gives your sending reputation a chance to recover.
Next, focus on improving your email list hygiene. This involves removing inactive subscribers, invalid addresses, and anyone who has explicitly complained or opted out. Ensure your list is built on explicit consent (opt-in) and regularly prune unengaged contacts. This helps you fix why emails go to spam.
After cleaning your list and reviewing your sending practices, it is beneficial to reach out to SFR.fr directly to understand the specific reasons for the block and discuss a resolution. This might involve contacting their abuse desk (often abuse@sfr.fr) or their postmaster team, as mentioned by Postmastery. Be prepared to demonstrate the changes you've made to improve your sending quality.
Example bounce handling logicpython
# Example: Pseudocode for handling email bounces
FUNCTION handle_bounce(bounce_email_address, bounce_code):
IF bounce_code == "GU_EIB_04":
log_warning("SFR.fr detected abuse for", bounce_email_address)
add_to_suppression_list(bounce_email_address, "SFR_GU_EIB_04")
send_alert_to_admin("High SFR.fr bounce rate detected")
ELSE IF bounce_code == "550 5.4.1":
log_info("Recipient access denied for", bounce_email_address)
mark_as_invalid(bounce_email_address)
ELSE:
log_info("General bounce for", bounce_email_address)
increment_temp_fail_counter(bounce_email_address)
FUNCTION add_to_suppression_list(email, reason):
# Add email to a list that prevents future sends
# This is critical for maintaining sender reputation
FUNCTION send_alert_to_admin(message):
# Notify relevant team members about deliverability issues
Maintaining good email hygiene with SFR.fr
To prevent future 'Abus detecte GU_EIB_04' errors and ensure long-term email deliverability with SFR.fr, proactive email hygiene is essential. One critical measure is to sign up for feedback loops (FBLs). For French ISPs, this often means leveraging platforms like Signal Spam. This service provides aggregated complaint data, allowing you to quickly identify and remove users who mark your emails as spam, which helps preserve your sender reputation.
Regularly monitor your domain reputation and IP reputation. Tools like Google Postmaster Tools (for Gmail) or other blocklist (or blacklist) monitoring services can provide insights into how your emails are performing. A sudden dip in reputation or an increase in bounce rates often signals an impending problem.
Finally, consistently deliver valuable and relevant content to your subscribers. Engagement is a strong positive signal to ISPs. Personalize your emails, send them at optimal frequencies, and always provide clear unsubscribe options. A highly engaged list is your best defense against spam filters and helps to boost email deliverability rates.
Best practice
Description
List hygiene
Regularly clean your email lists to remove inactive, invalid, or unengaged subscribers. This reduces bounces and complaints.
Authentication
Ensure your SPF, DKIM, and DMARC records are correctly configured. This verifies your sending legitimacy.
Content quality
Create engaging, relevant content, and avoid spammy keywords or excessive images. Maintain a good text-to-image ratio.
Feedback loops
Sign up for FBLs, like Signal Spam for SFR, to receive automated spam complaints.
Views from the trenches
Best practices
Actively manage your suppression lists, removing any recipients who trigger bounces or complaints.
Segment your audience based on engagement to send more relevant content, increasing positive interactions.
Implement a double opt-in process for all new subscribers to ensure explicit consent and reduce spam complaints.
Regularly monitor email sending volume and frequency to avoid sudden spikes that could trigger filters.
Common pitfalls
Ignoring early warning signs from bounce codes, leading to prolonged blacklisting and harder recovery.
Continuing to send emails to bounce addresses, which can quickly degrade your sender reputation.
Relying solely on external blacklist checkers without understanding ISP-specific filtering mechanisms.
Failing to adapt content and sending patterns based on regional ISP preferences and anti-spam rules.
Expert tips
For French ISPs, engage with Signal Spam to receive aggregated FBL data. This helps you manage complaints effectively.
Understand that some ISPs, especially those using VadeSecure, are highly sensitive to complaint rates, even for low volumes.
Don't just clean your list once, implement ongoing hygiene processes to maintain a healthy subscriber base.
Consider warming up new IPs or domains gradually to build a positive sending history with ISPs like SFR.fr.
Expert view
Expert from Email Geeks says SFR.fr utilizes an aggregated FBL, which tracks complaint counters per IP and per day. This means that a few complaints can quickly escalate into a temporary block.
2019-06-04 - Email Geeks
Expert view
Expert from Email Geeks says while the GU_EIB_04 error can indicate various issues, it primarily points to a high complaint rate. It might also stem from complaints on other ISPs that use the same anti-spam vendor, VadeSecure.
2019-06-04 - Email Geeks
Concluding thoughts on SFR.fr deliverability
The 'Abus detecte GU_EIB_04' error from SFR.fr is a clear signal that your email sending practices need immediate attention. By understanding its causes, implementing robust list hygiene, and proactively monitoring your sender reputation, you can resolve these blocks and ensure your emails consistently reach the inbox. Prioritizing legitimate sending, respecting recipient consent, and adapting to ISP feedback are paramount for successful email deliverability in the long run.
