Why are Bigpond emails bouncing with a content-based spam reason?
Updated on 4 Oct 2026: We clarified how to read an IB703 bounce and test content, authentication, and the sending route before retrying Bigpond recipients.
Bigpond emails bouncing with a content-based spam reason means Bigpond rejected that delivery attempt under its filtering policy. The wording does not identify the exact trigger: message content, links, sender reputation, authentication, complaint history, or sending pattern can all warrant investigation. It does not prove a permanent domain block. A bounce like IB703 is a signal to pause, isolate the affected campaign or message, and test before sending more mail to Bigpond recipients.
Treat it as a receiver-specific rejection first. Check whether the bounces are limited to one campaign, one sending IP, one template, one link set, one list segment, or a concentrated burst of Bigpond volume. If normal transactional mail reaches the same audience but one promotion fails, review that campaign first.
Typical Bigpond bounce text
558-5.7.1 Message content rejected due to suspected spam. IB703 558 5.7.1 i{a03ab15d-1d81-442c-964f-4a23c88f44cf}
What the Bigpond bounce means
A 5.7.1 response is a permanent policy rejection for that delivery attempt. It does not mean the recipient address is invalid or that every future message will fail. Bigpond rejected the message during the SMTP transaction instead of accepting it for delivery. The phrase "message content rejected" does not disclose which signal caused the decision. Review the subject line, body, links, sender and linked domains, authentication results, complaints, and sending cadence as separate hypotheses.
Read the remote server response in the full non-delivery report. A sending provider can wrap Bigpond's 558 5.7.1 IB703 response in its own delivery code. Keep that wrapper, but use the Bigpond response to identify this specific rejection. A different Bigpond code, such as IB302, needs its own diagnosis.
Start with the campaign and sending route, not the recipient address. If a small subset of a database has Bigpond addresses, one affected send can look small in total volume but still matter inside that receiver. Check what percentage of Bigpond attempts failed, whether failures cluster around one creative or time window, and whether the sender sees similar failures at other mailbox providers.
Do not keep retrying the same campaign
Repeatedly sending the same rejected content to Bigpond recipients can add reputation pressure. Pause the affected campaign, record IB703 as a policy rejection rather than proof of an invalid mailbox, follow the sending platform's bounce policy, and restart only after a controlled test succeeds.
Telstra Mail webmail screenshot showing a message filtering view.
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|
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|---|---|---|
IB703 | Content or policy rejection | Compare campaign and route |
Only Bigpond | Receiver-specific pattern | Segment report |
One campaign | Creative or links changed | Controlled test |
Many campaigns | Reputation or volume pressure | Sender audit |
Most likely causes
The bounce reason points toward content, but treat it as a combined content and sender-quality problem until the data narrows it down. Bigpond can reject a campaign when several signals cross its filtering threshold. A new offer, a changed link, a complaint increase, stale addresses, or a concentrated send can change the result.
- Campaign content can matter when copy, imagery, links, redirects, or reused templates differ from messages that delivered.
- Subject line symbols and emoji are test variables, not a known standalone cause of IB703.
- Complaint spikes can affect sender reputation even when the creative has not changed.
- A tracking domain, landing page, image host, or redirect chain can affect filtering even when the sending domain authenticates.
- Sudden volume spikes, concentrated Bigpond batches, or a shared outbound IP with a poor history can trigger receiver-specific rejection.
- SPF, DKIM, and DMARC failures can add risk. Passing authentication does not guarantee acceptance.
- If similar bounces appear at other consumer domains, check sender reputation, blocklist (blacklist) status, and list quality before editing copy.
When to pause Bigpond sends
Use the scope and recurrence of failures for internal triage. These are not Bigpond acceptance thresholds.
Isolated
One or few attempts
A single test or tiny recipient group fails.
Investigate
Repeated in one send
Failures cluster in one Bigpond campaign.
Pause
Repeated across sends
The same policy rejection recurs across sends or valid recipients.
The subject-line symbol question is worth testing, but it should be a hypothesis, not the diagnosis. Remove the symbol in one controlled test, then test the links, offer framing, and sender setup as separate variables.
The troubleshooting workflow
Use a narrow workflow for Bigpond content rejections because broad changes create noise. The aim is to test whether the rejection follows the message, sender, audience, sending pattern, or route.
Flowchart showing the steps for troubleshooting Bigpond bounce rejections.
- Save the full SMTP response, campaign ID, sending IP, domain, template, subject line, recipient domain, and timestamp.
- Calculate the rejection rate for Bigpond attempts separately from the whole campaign. A small domain share can hide a receiver-specific issue.
- Find the last Bigpond campaign that delivered normally and compare its subject, offer, template, link domains, send time, segment, volume, and sending route.
- Validate DMARC, SPF, DKIM, DNS, and mail-domain setup before blaming copy alone.
- Review IP and domain reputation, including blocklist (blacklist) status, so a listing is not mistaken for a copy issue.
- Send controlled variants to a small valid sample, changing one variable at a time.
- If authentication is clean and a simple content test still fails, contact the sending provider with the exact bounce, headers, sender IP, and sample message. Ask it to escalate the route to Telstra when it controls the outbound infrastructure.
Suped's domain health check can help validate authentication, while blocklist monitoring can show whether a sender IP or domain has a listing signal. Compare those findings with the actual Bigpond bounce and controlled tests.
If you send through a hosted mailbox provider
A personal or hosted mailbox provider usually controls the outbound IP, return-path, routing, and often DKIM signing. Changing the home or office internet connection normally does not change the cloud service's outbound mail server, so it is not a reliable test of the IP reputation Bigpond sees.
- Compose a new plain-text control message without a signature, attachments, tracking links, or pasted HTML. Converting the rejected HTML message can leave hidden markup behind.
- Check whether failures affect several valid Bigpond recipients on the same provider. A failure limited to one message still supports a content test.
- Give the sending provider the complete non-delivery report, timestamp with time zone, recipient domain, message headers, and a reproducible sample. It can inspect delivery logs and its shared route.
- Do not rely on recipient safelisting. An IB703 SMTP rejection happens before the message reaches mailbox-level junk or safe-sender rules.
Sending from another account can show whether the failure follows the original route, but it changes the sender identity and often the IP as well. Do not treat one successful alternate-account send as proof that the original message content was the cause. If the sender owns the domain and controls a bulk sending program, continue with authentication, audience, reputation, and cadence checks. If the sender uses a consumer mailbox, focus on evidence and provider escalation.
How to test content without guessing
Content testing works when the variants are controlled. Do not rewrite everything at once. If the rejected campaign had a symbol in the subject line, a video link, several tracked URLs, and a new promotional claim, changing all of those together shows only that the second version was different.
Start with the smallest useful test: the same sender, authenticated domain, segment type, and time window, but use a new plain-text message without a signature, attachments, tracking, or pasted HTML. Then test links separately. If a link-free message delivers and a version with tracked links fails, investigate the URL and redirect chain. Repeat with a small valid sample before assigning a cause. If the plain-text control also fails, investigate sender reputation, the sending route, volume, and recipient policy.
Before sending another Bigpond batch, use Suped's email tester to inspect the message, authentication, headers, copy, and visible deliverability issues. The test does not replace delivery to a real Bigpond mailbox, but it can catch avoidable mistakes before another send.
Email tester
Send a real email to this address. Suped shows a results button when the test is ready.
?/43tests passed
Campaign-specific rejection
- One campaign or a small number of closely related messages fail.
- Previous Bigpond sends were normal and other receivers look stable.
- Edit the campaign and retest with a small valid sample.
Broader sender problem
- Multiple campaigns, domains, or consumer receivers show rejection pressure.
- Complaints, low engagement, authentication gaps, listing signals, or volume spikes appear together.
- Pause risky segments, repair authentication, reduce concentrated volume, and rebuild reputation.
Separate creative review from list review. An email to an old, unengaged audience can generate complaints even when its copy is clear. If the Bigpond segment has old addresses, low engagement, or recent complaint pressure, clean the audience before tuning the subject line again.
Where Suped fits
Suped is our DMARC reporting and email authentication product. For an IB703 investigation, it puts authentication results, authorized sender sources, domain health, and blocklist (blacklist) signals beside the bounce evidence. Suped cannot override Bigpond's filter or reveal the exact rule behind an IB703 response, but it can show whether an authentication or sender-source problem needs to be fixed before more content tests.
Use Suped's DMARC monitoring to confirm which sources send for the domain, whether DMARC passes with domain alignment, and whether unknown sources appear. Aggregate DMARC reports show authentication patterns; they do not identify the specific rule that produced an IB703 bounce. Pair them with the sender IP, full bounce, campaign comparison, and controlled message tests.
Issue steps to fix dialog showing the issue overview, tailored fix steps, and verification action
- Suped flags misconfigured authentication and provides repair steps for DNS and domain alignment.
- Alerts identify authentication or sender-source changes that coincide with the start of Bigpond rejection pressure.
- Hosted DMARC, hosted SPF, SPF flattening, and hosted MTA-STS can reduce DNS work when a controlled authentication change is required.
- Teams managing many domains can compare sender health and see whether the issue extends beyond one Bigpond campaign.
If authentication is clean, sources are verified, and blacklist or blocklist checks show no listing signal, continue the campaign-specific, cadence, shared-route, or false-positive investigation. If Suped shows unknown senders, SPF lookup pressure, broken DKIM, or listing signals, fix those issues before asking the sending provider or Telstra to review the rejection.
When to contact your provider or Telstra
Contact the sending provider first when it controls the outbound IP or shared mail route. Escalate after the problem is reproducible, the content has been simplified, and affected recipients are valid. Contact Telstra support when the sending route has been checked or when the sending provider asks for receiver-side review. Include the exact remote-server diagnostic, because a general report that mail is bouncing gives either team little to investigate.
What to include in the escalation
- Provide the full SMTP response, date, time zone, sending IP, envelope sender, header From domain, and affected recipient domain.
- Provide a copy of the rejected message with headers, subject, HTML, plain text, and every link domain.
- Provide SPF, DKIM, and DMARC results for the rejected send, plus recent DNS or sender-source changes.
- Describe the content and cadence tests already run, the signals changed, and whether the issue still reproduces.
If the sending provider or Telstra confirms that the campaign tripped a filter, fix the underlying signal before resuming volume. If the case is treated as a false positive, keep the cleaned message and watch the next several sends. Repeated failures call for another review of content, reputation, the shared route, and cadence.
Views from the trenches
Best practices
Compare the blocked send with the last Bigpond campaign that delivered cleanly before editing.
Pause repeat sends to affected Bigpond recipients until a controlled test stops the rejection.
Send provider evidence with headers, bounce text, sender IP, and the cleaned message sample.
Common pitfalls
Blaming a subject symbol first can hide link reputation, complaints, or stale audience issues.
Retrying the same rejected creative adds failed attempts and can add reputation pressure.
Looking only at total bounce rate can hide a severe issue inside the Bigpond recipient segment.
Expert tips
Test one variable at a time, starting with links, subject symbols, and the plain text version.
Track Bigpond separately from the full campaign so small domain share does not mask real pressure.
Keep DMARC, SPF, DKIM, and blocklist data beside content tests to avoid false diagnosis.
Expert view
Expert from Email Geeks says the IB703 rejection is most consistent with content-based filtering and should be treated as a warning sign, even when only a small segment is affected.
2023-11-14 - Email Geeks
Marketer view
Marketer from Email Geeks says receiver-side review can identify campaign issues or adjust filtering when a specific rejection is a false positive.
2023-11-15 - Email Geeks
What to do next
A Bigpond content-based bounce is a deliverability warning. Pause that campaign for Bigpond recipients, preserve the bounce data, compare it with a clean send, validate authentication, review link and domain reputation, check sending cadence, and run a small controlled content test before resending.
If the issue disappears after simplifying the message, document the changed variable and confirm the pattern with another small test. If it continues across plain content and clean authentication, escalate with evidence to the team that controls the sending route. Suped helps organize the authentication and sender-source evidence, including DMARC, SPF, DKIM, and blocklist (blacklist) signals.
