Summary
Soft bounces from Windstream, TDS, CenturyTel, Hughes, and Zoom Internet may arise from a combination of factors. Temporary issues like full mailboxes and server outages are common, but potential spam flagging, inbox placement concerns, and reputation issues (related to domain, IP, or email content) should also be investigated. The 'VI' code suggests VADE spam filtering is a factor, and greylisting or snowshoe spamming could be affecting deliverability. Recurring soft bounces may indicate more significant deliverability problems needing proactive intervention.
Key findings
- Temporary Issues: Mailbox full, server down, message size too large cause soft bounces.
- VADE Filtering: 'VI' code indicates VADE spam filtering; use their sender tool to check status.
- Spam Flagging: Emails may be flagged as spam due to content or sender reputation.
- Reputation Impact: Domain, IP, and content influence sender reputation and deliverability.
- External Spamming: Snowshoe spamming (bad IP neighbors) can affect IP reputation.
- Greylisting: Receiving servers may temporarily reject emails (greylisting) to verify legitimacy.
Key considerations
- Use VADE Sender Tool: Check if emails are blocked by VADE.
- Monitor Reputation: Track domain and IP reputation; address any negative trends.
- Review Email Content: Optimize content to avoid spam triggers (suspicious words, large images).
- Email Authentication: Implement SPF, DKIM, and DMARC for email authentication.
- Blacklist Monitoring: Check for IP or domain listing on email blacklists.
- Bounce Analysis: Analyze bounce patterns to pinpoint specific problems or ISPs.
What email marketers say
8 marketer opinions
Soft bounces from Windstream, TDS, CenturyTel, Hughes, and Zoom Internet can stem from various temporary issues, ranging from full mailboxes and server problems to potential spam flagging and deliverability concerns. These issues can be related to sender reputation, IP blacklisting, or the content of the emails themselves.
Key opinions
- Temporary Issues: Soft bounces often indicate temporary problems like a full inbox or server outages.
- Potential Spam: Soft bounces can signify that emails are being flagged as spam and delayed.
- Inbox Placement: Consistent soft bounces may indicate inbox placement problems, meaning emails are not reaching recipients' inboxes.
- Reputation: Domain and sender IP reputation can impact deliverability and lead to soft bounces.
- Content: Email content, including suspicious words or large images, might trigger spam filters and cause soft bounces.
Key considerations
- Monitor Reputation: Regularly check your sender and domain reputation to identify and address any negative trends.
- Review Content: Carefully examine email content for spam triggers, such as excessive punctuation or suspicious wording.
- Authenticate Emails: Ensure proper email authentication (SPF, DKIM, DMARC) to improve deliverability.
- Check Blacklists: Verify if your IP address or domain is listed on any email blacklists.
- Evaluate Bounce Patterns: Analyze bounce patterns to identify specific issues, like consistent failures with particular ISPs.
Marketer view
Email marketer from Mailjet explains that soft bounces occur when the recipient's mailbox is full, the server is down, or the message size is too large. They also state that soft bounces can sometimes indicate temporary deliverability issues.
20 Apr 2022 - Mailjet
Marketer view
Email marketer from EmailOnAcid highlights that soft bounces could be caused if your IP address has been listed on a blocklist. Suggesting you use tools such as the MultiRBL tool.
17 Feb 2023 - EmailOnAcid
What the experts say
5 expert opinions
Soft bounces from Windstream, TDS, CenturyTel, Hughes, and Zoom Internet might be related to VADE spam filtering. Could also stem from greylisting, potential reputation problems, or 'snowshoe spamming' making filtering difficult. Checking the VADE sender tool is also recommended.
Key opinions
- VADE Spam Filtering: The 'VI' code in bounce messages suggests the use of VADE, a spam filtering service, by these ISPs.
- Greylisting: Soft bounces can be caused by greylisting, where receiving servers temporarily reject emails to verify senders.
- Reputation Issues: Soft bounces may indicate underlying reputation problems with sending IPs.
- Snowshoe Spamming: Snowshoe spamming by other senders can impact IP reputation and cause delivery issues, resulting in soft bounces.
Key considerations
- VADE Sender Tool: Use the VADE sender tool to check if your emails are being blocked by their system.
- Check Blocklists: Proactively monitor your sending IPs for inclusion on email blocklists.
- Monitor Reputation: Continuously monitor and maintain a good sending reputation to avoid greylisting and other filtering issues.
Expert view
Expert from Spamresource explains that soft bounces can be caused by greylisting, where the receiving server temporarily rejects the email to verify the sender's legitimacy.
16 Mar 2025 - Spamresource
Expert view
Expert from Email Geeks identifies that 'VI' likely refers to VADE, a spam filtering service.
2 Mar 2025 - Email Geeks
What the documentation says
2 technical articles
SMTP enhanced status codes (4.X.X) indicate temporary email delivery failures, consistent with soft bounces. Services like AWS SES treat soft bounces as temporary, attempting redelivery before classifying them as hard bounces if failures persist.
Key findings
- SMTP Codes: 4.X.X SMTP enhanced status codes signify transient delivery failures (soft bounces).
- Temporary Issue: Soft bounces stem from temporary delivery issues.
- Redelivery Attempts: AWS SES attempts redelivery of soft bounced emails.
- Hard Bounce Escalation: Continued soft bounces can escalate to hard bounces.
Key considerations
- Monitor Bounces: Regularly monitor soft bounce rates to identify potential underlying issues.
- Understand Codes: Investigate specific SMTP status codes to understand the cause of soft bounces.
- Temporary vs Permanent: Differentiate between temporary soft bounce issues and potential long-term deliverability concerns.
Technical article
Documentation from AWS Simple Email Service (SES) categorizes bounces as hard or soft. Soft bounces can be due to temporary issues, and SES will attempt to redeliver the email for a period. Continued soft bounces will eventually result in a hard bounce.
22 Oct 2021 - AWS
Technical article
Documentation from RFC Editor explains that SMTP enhanced status codes provide detailed information about delivery problems. A 4.X.X code generally indicates a transient failure, which aligns with the definition of a soft bounce.
19 Sep 2021 - RFC Editor
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