Summary
Consistently sending emails to 'over quota' addresses negatively impacts sender reputation. Gmail shares storage across its services, leading to such bounces when limits are reached. Experts recommend a multi-faceted approach including bounce management, immediate suppression of repeat offenders, list segmentation based on engagement, and strict list hygiene practices. RFC standards dictate these bounces should be treated as permanent failures. Ignoring 'over quota' bounces significantly harms deliverability and sender reputation.
Key findings
- Gmail Storage Limits: Gmail shares 15GB storage across Drive, Gmail, and Photos; exceeding this leads to bounces.
- Reputation Damage: Ignoring 'over quota' bounces severely impacts sender reputation.
- Bounce as Permanent Failure: RFC standards classify 'over quota' bounces as permanent failures.
- Immediate Suppression: Suppressing recipients with recurring 'over quota' bounces is crucial.
- List Hygiene Essential: Maintaining a clean and engaged email list is vital to reduce 'over quota' issues.
- Proactive Action Needed: Bounces should be proactively processed to prevent negative impacts on sender reputation.
Key considerations
- Bounce Management: Implement a comprehensive bounce management strategy.
- Engagement Segmentation: Segment lists based on engagement and send less frequently to unengaged users.
- Automated Suppression: Use automated rules for immediate suppression of 'over quota' addresses.
- Provider Guidelines: Follow email provider guidelines and best practices for handling bounces.
- Double Opt-In: Implement double opt-in to ensure high-quality email addresses.
- Monitor Bounce Rates: Closely monitor bounce rates as a key indicator of list health.
- Address Temporary Failures: Understand and act upon temporary bounce codes to maintain a good sender reputation.
What email marketers say
10 marketer opinions
Consistently sending emails to 'over quota' addresses negatively impacts sender reputation. Experts recommend implementing a bounce management strategy, segmenting lists based on engagement, and immediately suppressing users who trigger overquota bounces. Maintaining list hygiene and promptly addressing bounce messages are crucial for deliverability.
Key opinions
- Sender Reputation Impact: Ignoring 'over quota' bounces damages sender reputation over time.
- Automated Suppression: Setting up automated bounce rules for consistent 'over quota' errors helps maintain list quality.
- Segmentation Strategy: Segmenting lists and reducing frequency to less engaged users can prevent quota issues.
- Bounce Categorization: 'Over quota' bounces are often categorized as hard bounces, indicating a permanent issue.
- Importance of List Hygiene: Proactive email list cleaning and management are essential to preventing deliverability issues caused by 'over quota' bounces.
Key considerations
- Provider Rules: Follow email provider's bounce rules to effectively manage bounces.
- Storage Limits: Gmail's storage is shared across multiple services, which should be kept in mind when sending emails.
- Double Opt-In: Implement a double opt-in process to ensure validity of email addresses.
- Re-engagement Campaigns: Consider re-engaging inactive subscribers before permanently suppressing them.
- List Cleaning: Remove email addresses which result in bounces.
Marketer view
Email marketer from SendGrid explains that managing bounces, including 'over quota' bounces, is crucial for maintaining a good sender reputation. They recommend automatically removing recipients who consistently trigger bounces from your sending list.
16 Aug 2022 - SendGrid
Marketer view
Email marketer from OptinMonster recommends cleaning your email list regularly to improve deliverability. Overquota bounces are an indicator of low-quality addresses which should be removed.
18 Dec 2024 - OptinMonster
What the experts say
2 expert opinions
Experts emphasize that correctly processing bounces, including temporary failures like 'over quota' errors, is crucial for maintaining a good sender reputation. Good list hygiene practices, including monitoring and acting upon bounce metrics, are essential for effective email deliverability. Ignoring bounces negatively impacts sender reputation.
Key opinions
- Bounce Processing Importance: Correctly processing bounces, including temporary failures, is vital for sender reputation.
- List Hygiene: Good list hygiene, including actioning bounce metrics, is crucial for maintaining sender reputation and effective deliverability.
- Impact of Ignoring Bounces: Ignoring bounces negatively impacts sender reputation.
Key considerations
- Temporary Failures: Understand and act upon temporary bounce codes to maintain a good sender reputation.
- Bounce Monitoring: Closely monitor bounce rates and patterns as critical metrics for understanding list hygiene.
- Action on Bounces: Take appropriate action on bounce notifications, which may include removing or suppressing addresses.
Expert view
Expert from Spamresource.com explains that having good list hygiene practices is critical to maintaining sender reputation. They explain that bounces are a critical metric for understanding list hygiene and must be actioned. Although not directly answering the question, overquota errors are bounces which must be managed effectively.
14 Aug 2021 - Spamresource.com
Expert view
Expert from Word to the Wise explains that bounces should be processed correctly, including temporary failures. While this article doesn't mention overquota specifically, understanding and acting upon temporary bounce codes which is what overquota is, is critical for maintaining a good sender reputation. Ignoring these impacts sender reputation.
9 Jan 2024 - Word to the Wise
What the documentation says
4 technical articles
Gmail shares storage across Google Drive, Gmail, and Google Photos. When this limit is reached, 'over quota' bounces occur. RFC standards dictate 'over quota' errors should be treated as permanent failures. Sending to these addresses negatively impacts sender reputation and deliverability on platforms like AWS SES and Microsoft. Removing such addresses is advised.
Key findings
- Shared Storage: Gmail's storage is shared across multiple services.
- Permanent Failure: 'Over Quota' errors should be treated as permanent failures according to RFC standards.
- Sender Reputation Impact: Sending to full mailboxes negatively affects sender reputation and deliverability.
- Account Deletion Risk: Accounts exceeding storage limits for 2 years are at risk of having emails deleted.
Key considerations
- Storage Limits: Be aware of Gmail's storage limits and the impact on receiving emails.
- Bounce Handling: Handle 'over quota' bounces as permanent failures in accordance with RFC standards.
- List Management: Remove email addresses resulting in 'over quota' bounces to protect sender reputation.
- NDRs: Mailbox full issues result in non-delivery reports (NDRs) that can impact sender reputation.
Technical article
Documentation from Microsoft states that mailbox full issues will result in a non-delivery report which impacts your sender reputation. It suggests removing email addresses which result in bounces.
11 Feb 2023 - Microsoft
Technical article
Documentation from AWS SES explains that when a recipient's mailbox is full ('over quota'), it results in a bounce. Repeatedly sending to these addresses negatively impacts your sender reputation and deliverability.
6 Jun 2025 - Amazon Web Services
Can a hard bounced email address become deliverable again, and under what circumstances?
Do soft bounces affect email deliverability and sender reputation?
How are email bounce rates calculated and what is considered a good bounce rate?
How do Gmail 'mailbox full' bounces affect email deliverability and how can I monitor it?
How should email marketers handle 452 mailbox full bounce codes, especially from Gmail, during email warmup?
How should email marketers handle Gmail addresses with overquota inboxes?
How should email marketers handle permanent bounce errors like full or inactive mailboxes?
