Summary
Pausing email sending negatively impacts IP reputation, especially for newly warmed IPs. While long-term IPs are more resilient, any pause causes some degree of degradation. Maintaining consistent sending volume and frequency is crucial. Gmail is more tolerant of fluctuations than Yahoo and Hotmail/Office 365. It's best to inform ISPs about warmups and, if possible, postpone warmups until after planned pauses. Avoid pausing a warmup that has started. A consistent, though lower, volume is better than spikes followed by pauses.
Key findings
- IP Cooling Effect: IP reputation begins to degrade immediately upon pausing sending.
- Warmed IP Vulnerability: Newly warmed IPs are significantly more vulnerable to pauses than long-term IPs.
- ISPs Differ in Sensitivity: Gmail is more tolerant of volume fluctuations compared to Yahoo and Hotmail/Office 365.
- Consistency is Paramount: Consistent sending volume and frequency are critical for maintaining a positive IP reputation.
Key considerations
- Avoid Pauses During Warmup: Avoid pausing sending during IP warm-up, as it can undo the progress made.
- Prioritize Consistent Volume: Prioritize consistent sending volume over infrequent bursts, even if the volume is lower.
- Inform ISPs of Warmup: Inform Yahoo and Hotmail/Office 365 about IP warmups to potentially mitigate negative impacts.
- Delay Warmup if Pause is Planned: If a pause is anticipated, delay the IP warm-up until after the pause to maintain consistency.
What email marketers say
7 marketer opinions
Pausing email sending, especially after warming up an IP, negatively affects IP reputation. While Gmail is more tolerant, Yahoo and Hotmail/Office 365 prioritize consistent volume. Maintaining a consistent sending schedule is essential, particularly for newly warmed IPs, as pauses can undo the progress made.
Key opinions
- Negative Impact on Reputation: Pausing email sending harms IP reputation, especially for newly warmed IPs.
- Inconsistency Concerns: Sudden changes in sending volume or frequency negatively affect sender reputation.
- Gmail Tolerance: Gmail is more tolerant of inconsistent sending compared to Yahoo and Hotmail/Office 365.
- Newly Warmed IPs: Pauses after warming IPs are particularly damaging, undoing the progress made.
Key considerations
- Maintain Consistency: Maintain a consistent sending schedule to avoid negatively impacting IP reputation.
- Inform ISPs: Inform Yahoo and Hotmail/Office 365 about IP warmups to mitigate potential issues.
- Postpone Warmup: If possible, postpone warming up IPs until after a planned pause to maintain a consistent ramp-up.
- ISPs sensitivity: Be aware that various ISPs have different sensitivity to inconsistent volume of email sending.
Marketer view
Email marketer from Mailjet explains that sudden changes in sending volume or frequency can negatively affect sender reputation. It's essential to maintain a consistent sending schedule, particularly for warmed IPs.
9 Sep 2024 - Mailjet
Marketer view
Email marketer from GlockApps responds that sending frequency and consistency are key factors in sender reputation. Taking a break from sending, especially after a warm-up, can hurt your IP's reputation.
4 Nov 2023 - GlockApps
What the experts say
4 expert opinions
Pausing email sending negatively impacts IP reputation, especially for newly warmed IPs. While long-term IPs are more resilient, any pause causes some degree of 'cooling down.' Maintaining consistent sending volume is crucial; it's better to have a lower, consistent volume than spikes followed by pauses. To avoid complications, it's advised to avoid pausing a warmup that has started.
Key opinions
- IP Cooling: IPs start to 'cool down' immediately when sending is paused.
- Warmed IP Vulnerability: Newly warmed IPs are significantly more vulnerable to the negative impacts of pausing sending.
- Long-Term IP Resilience: Long-term IPs are more resilient to pauses, but still experience some negative impact.
- Consistency is Key: Maintaining consistent sending volume is crucial for IP reputation.
Key considerations
- Avoid Pauses During Warmup: Avoid pausing email sending during the IP warmup process.
- Prioritize Consistency: Prioritize consistent sending volume over infrequent bursts.
- Lower Volume Option: If necessary, maintain a lower, consistent sending volume rather than stopping completely.
Expert view
Expert from Email Geeks explains that IPs start to cool down immediately during a pause, but the impact is less significant on long-term IPs.
14 Jul 2023 - Email Geeks
Expert view
Expert from Email Geeks explains that a 2-week pause is very concerning after only 4 weeks of sending, but not as concerning for an IP used regularly for years. She advises not starting the warmup until after the pause to avoid complications.
14 May 2025 - Email Geeks
What the documentation says
4 technical articles
Pausing email sending negatively impacts IP reputation, especially for newer IPs that have not established a strong sending history. Consistent sending volume is crucial for maintaining a positive IP reputation, and pausing during IP warm-up is particularly detrimental as it disrupts the establishment of a consistent sending pattern.
Key findings
- Consistent Sending is Key: Consistently sending emails helps maintain a positive sender reputation.
- Negative Impact of Pauses: Pauses in sending can negatively impact IP reputation.
- Detrimental to Warm-up: Pausing sending during IP warm-up disrupts the establishment of a consistent sending pattern.
- New IPs at Risk: Newer IPs are more vulnerable to reputation damage from sending pauses.
Key considerations
- Avoid Pauses: Avoid pausing sending, especially during the IP warm-up phase.
- Maintain Consistency: Maintain a consistent sending volume to protect IP reputation.
- Ramp-Up Carefully: If starting from a new IP, carefully ramp up sending volume to establish a solid reputation.
Technical article
Documentation from Microsoft responds that consistent sending volume is crucial for maintaining a positive IP reputation with Outlook. A sudden stop in sending can lead to deliverability issues, especially for newly warmed IPs.
28 Jul 2024 - Microsoft
Technical article
Documentation from Google explains that consistently sending emails helps maintain a positive sender reputation. Pauses can negatively impact this reputation, especially for newer IPs that haven't built a strong history.
17 Mar 2024 - Google
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