Summary
The consensus is that while Mailosaur, when used correctly, aims to simulate real user behavior without negatively impacting deliverability, sending to invalid, non-existent, or spam trap addresses—even for testing purposes—can harm sender reputation over time. Experts recommend caution regarding excessive test emails, especially via Gmail, and emphasize maintaining good list hygiene, regular validation, and monitoring bounce and spam rates to mitigate risks. Address harvesting should be avoided.
Key findings
- Reputation at Risk: Sending test emails to invalid or spam trap addresses harms sender reputation.
- Hygiene is Key: Maintaining good list hygiene is crucial for improved deliverability.
- Bounce Matters: High bounce rates from invalid addresses negatively affect sender reputation.
- Mailosaur's Intent: Proper Mailosaur usage aims to simulate user behavior without triggering spam filters.
- Gmail Limits: Exceeding Gmail limits when testing can cause mail delays.
- Harvesting Hurts: Address harvesting leads to invalid addresses and spam traps.
Key considerations
- Validate Lists: Regularly validate email lists to remove invalid addresses.
- Limit Testing: Avoid excessive testing, especially with Gmail, to prevent delays.
- Monitor Metrics: Monitor bounce and spam rates to identify deliverability issues.
- Avoid Harvesting: Refrain from address harvesting to prevent spam traps.
- Strategic Testing: Implement strategic email testing to minimize negative impacts.
- Use Tools Wisely: If using Mailosaur, do so in the way it was intended, by simulating real user behaviour.
What email marketers say
8 marketer opinions
The impact of Mailosaur test email addresses on email deliverability is complex. While Mailosaur itself, when used correctly, aims to simulate real user behavior without triggering spam filters, sending emails to invalid, non-existent, or spam trap addresses – even for testing purposes – can negatively affect sender reputation over time. This is primarily due to increased bounce rates and potential identification as a sender with poor list hygiene. Therefore, maintaining a clean and validated email list and utilizing appropriate testing practices are crucial to mitigating these risks.
Key opinions
- Reputation Risk: Sending test emails to invalid addresses or spam traps can harm sender reputation.
- Bounce Rate Impact: High bounce rates from invalid test addresses negatively affect deliverability.
- Mailosaur Usage: Proper use of Mailosaur aims to simulate real user behavior without triggering spam filters.
- List Quality Matters: Email list quality is critical for maintaining a good sender reputation and deliverability.
Key considerations
- List Validation: Regularly validate and clean email lists to remove invalid or harmful addresses.
- Testing Practices: Use real email addresses or reputable testing tools like Litmus or Email on Acid for email campaign testing.
- Monitor Metrics: Monitor bounce rates and sender reputation to identify and address potential deliverability issues.
- Correct Mailosaur Use: Ensure Mailosaur is used correctly to simulate real user behavior and avoid spam filters.
Marketer view
Email marketer from Email on Acid shares best practices for testing email campaigns. While testing is essential, it's important to use real email addresses or testing tools like Litmus or Email on Acid itself to avoid potential deliverability issues associated with spam traps.
14 Jan 2024 - Email on Acid
Marketer view
Email marketer from Gmass explains that the quality of your email list is critical for maintaining a good sender reputation and deliverability. Sending to invalid or spam trap email addresses can increase your bounce rate and damage your reputation.
1 Jun 2022 - Gmass
What the experts say
5 expert opinions
While using Mailosaur for testing may not cause long-term deliverability issues, experts advise caution. Excessive test emails, especially when sent rapidly or via Gmail, can trigger mail delays and potential blocks. Mailosaur itself is likely not directly tied to major reputation engines, minimizing immediate damage. However, practices like address harvesting, which can lead to invalid addresses and spam traps, should be avoided to maintain good deliverability and feedback loop health.
Key opinions
- Excessive Testing: Excessive test emails can cause mail delays and potential blocks, particularly with Gmail.
- Reputation Engines: Mailosaur is likely not directly connected to major reputation feedback loops.
- Address Harvesting: Address harvesting can lead to invalid addresses and spam traps, harming deliverability.
- Potential Problems: Test emails could cause problems, and temporarily pausing sending may be necessary.
Key considerations
- Limit Testing: Avoid excessive testing, especially with Gmail, to prevent mail delays.
- Monitor Sending: Carefully monitor sending practices and temporarily pause if problems arise.
- Avoid Harvesting: Refrain from address harvesting to prevent issues related to invalid addresses and spam traps.
- Strategic Approach: Adopt a strategic approach to email testing to minimize potential negative impacts.
Expert view
Expert from Email Geeks shares that mailasaur is hosted on Google Cloud and likely not tied to any big reputation engine, minimizing potential reputation damage.
15 Sep 2022 - Email Geeks
Expert view
Expert from Email Geeks responds that the test emails could cause problems and suggests temporarily pausing sending.
13 Feb 2022 - Email Geeks
What the documentation says
5 technical articles
Email deliverability is significantly affected by the quality of email lists and the practice of sending to test addresses. Documentation from various sources emphasizes that sending to invalid, bouncing, or spam trap email addresses, including those used for testing, can negatively impact sender reputation and lead to deliverability issues. Maintaining good list hygiene, regular validation, and monitoring of bounce and spam rates are critical for ensuring successful email delivery.
Key findings
- List Hygiene: Maintaining good list hygiene is essential for improved deliverability.
- Bounce Rates: High bounce rates due to invalid test addresses negatively affect sender reputation.
- Spam Rates: High spam rates, often from outdated or test addresses, harm sender reputation and deliverability.
- Address Validation: Email addresses can be checked against a list of valid addresses to reduce undeliverable messages.
Key considerations
- Regular Cleaning: Regularly clean email lists to remove invalid or outdated addresses.
- Monitor Bounce Rates: Monitor and manage bounce rates to identify and address deliverability issues.
- Monitor Spam Rates: Monitor spam rates to ensure your sending practices are not flagged as problematic.
- Use Validation Tools: Employ email validation tools to verify addresses before sending.
Technical article
Documentation from SendGrid answers that high bounce rates, often caused by sending to invalid or test email addresses, can negatively affect your sender reputation. Monitoring and managing bounce rates is crucial for maintaining good deliverability.
14 Feb 2025 - SendGrid
Technical article
Documentation from Google Postmaster Tools explains that high spam rates, often resulting from sending to outdated or test email addresses, can significantly harm your sender reputation and lead to deliverability issues. Monitoring spam rates is crucial for identifying and addressing these problems.
3 Aug 2022 - Google Postmaster Tools
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