Instantly deliverability troubleshooting checklist

Instantly deliverability troubleshooting starts by naming the broken outcome. A campaign that stopped sending is different from a message that bounced. A bounce is different from a message accepted and placed in spam. Low replies are different again.

Do not change DNS, replace mailboxes, and rewrite copy at the same time. Preserve the evidence, classify the failure, fix one cause, then rerun the same check.

Classify the Instantly symptom first

Use Instantly’s campaign status, account status, bounce, and inbox placement evidence to place the problem in one row.

Symptom	What it proves	Check first
Campaign paused or no sends	Instantly did not complete the planned send	No account selected, account paused or disconnected, daily limit, slow ramp, plan status
Auto-paused for high bounces	Bounce rate crossed the threshold after 200+ sends	Bounce categories, SMTP responses, sender, recipient provider
Hard bounce	The recipient address or domain permanently rejected the message	Address validity, recipient MX, list source, verification
Soft bounce	A temporary failure, or a reputation or gateway block	SMTP response, sender reputation, blocklists, content, throttling
Message is in spam	The receiver accepted the message and filtered it	Reputation, message headers, links, content, complaints, recipient policy
Opens or replies fell	Campaign performance changed	First prove sends and acceptance, then review placement and message fit

These rows can overlap. One disconnected mailbox can reduce send volume while other accounts keep the campaign active. One bad lead segment can raise bounces without affecting every sender. Work at account, domain, campaign, and recipient-provider level instead of relying on one workspace-wide average.

1. Confirm the campaign and accounts actually sent

Start inside Instantly. Check the campaign status, the sending schedule, the assigned accounts, and recent send counts. Open the Email Accounts dashboard and filter by paused or error state to find the affected accounts.

Confirm:

• At least one sending account is selected on the campaign.
• The campaign is active and has an open sending window.
• Assigned accounts are connected and not paused or in error.
• Each account has available daily volume and is not capped by the slow-ramp setting.
• The plan is active, since an expired trial or plan pauses accounts, warmup, and campaigns.
• Leads remain eligible for the next step in the sequence.

Instantly’s campaign not sending guide walks through these states, and its campaign error guide covers account-level failures. Account or setting changes can take 10 to 15 minutes to apply, so re-check counts after a short wait rather than restacking changes.

Compare planned sends with completed sends by account. If the count dropped because two accounts disconnected, there is no placement result to diagnose for the messages that never left.

2. Read the high-bounce auto-pause before you resume

Instantly’s high-bounce auto-pause is enabled by default. It pauses a campaign once the bounce rate passes the threshold, 5% by default and adjustable in Preferences, after the campaign has sent at least 200 emails. After you fix the cause and resume, that campaign is not auto-paused for high bounces again for 7 days.

Treat the auto-pause as a signal, not a fix. Resuming without classifying the bounces spends that grace window and can add more reputation damage. Preserve, for every bounce cluster:

• The full SMTP response code and text.
• The Instantly bounce type.
• Sending account and domain.
• Recipient domain and mailbox provider.
• Campaign, sequence step, and timestamp.

3. Separate hard bounces from soft bounces

Instantly’s bounce guide separates hard bounces, soft bounces, and unknown bounces. The categories require different actions.

• A hard bounce is a permanent failure: an invalid address, a domain that does not exist, or a deleted mailbox. A 550 no such user spread across many domains points toward list quality, not your sending identity.
• A soft bounce is a temporary failure, or a reputation or gateway block. A 421 or policy rejection concentrated at one provider points toward throttling or reputation. A full mailbox, an unavailable server, or an email security gateway can also produce a soft bounce.

A cluster on a single account points toward that account or its sending identity. A cluster at one recipient provider points toward reputation or throttling at that provider.

Use the cold email bounce rate troubleshooting checklist when the main symptom is rejection. Use the recipient domain preflight checker to find dead domains, missing MX records, free inboxes, and common security gateways before another send.

4. Verify SPF, DKIM, DMARC, and MX outside the dashboard

A green setup state can become stale after a DNS change, mailbox migration, or provider change. Read the live records and compare them with a received message.

Confirm:

• The sending domain has working MX records.
• Exactly one SPF record exists and includes every active sending source.
• SPF stays within the 10 DNS lookup limit.
• DKIM is enabled and the selector in the message exists in DNS.
• The DKIM d= domain or SPF identity aligns with the visible From domain for DMARC.
• The DMARC record is valid and published at the correct policy domain.

Instantly’s bounce guide directs operators to verify MX, SPF, DKIM, and DMARC and to test domain configuration from the Email Accounts dashboard. Do not stop at record presence. A DKIM record can exist under an old selector while the current message signs with another one.

Run the SPF, DKIM, and DMARC checker for a combined public lookup. Then inspect Authentication-Results, DKIM-Signature, From, and Return-Path in one message received from the live campaign.

5. Check warmup and sending changes

Warmup is an operating signal, not proof that a live campaign will reach the inbox. Still, a stopped or failed warmup can reveal a disconnected account, an expired plan, a provider limit, a bounce event, or a block.

Confirm:

• Warmup is enabled for the intended account.
• Warmup sends and replies have not gone flat.
• The account can send and receive a manual test.
• The daily ramp did not jump after a quiet period.
• Live campaign volume fits the age and history of the domain and account.
• No provider limit or cool-off period is suppressing activity.

Instantly’s warmup not sending guide covers account connection, plan status, DNS, and warmup activity. If Instantly shows an account issue, record the stated reason before reconnecting or replacing anything.

Do not respond to a placement drop by increasing warmup and live volume together. Hold volume, fix the identified failure, and resume gradually with a measured segment.

6. Read inbox placement results by folder and provider

Instantly’s inbox placement tests send a message to seed mailboxes across major providers and report where it landed. The folder result changes the next action.

Placement result	Next investigation
Inbox	Compare by provider and preserve the test configuration
Promotions or Updates	Review content, links, and sending patterns for that provider
Spam	Inspect reputation, content, links, headers, cadence, and provider-specific patterns
Missing or not delivered	Check whether the sender completed the send, then look for rejection or routing evidence

Instantly also offers automated placement tests that can pause a campaign when placement drops below a threshold. Treat the result as a sample. A seed result says what happened to those messages at that time. It cannot prove placement for a different recipient, corporate gateway, message, or future send.

7. Inspect the message that was actually received

If SPF, DKIM, and DMARC pass but a message lands in spam, stop editing authentication records. The remaining evidence lives in reputation, sending behavior, the message surface, and recipient filtering.

Inspect:

• The connecting IP and every Received hop.
• SPF, DKIM, DMARC, and alignment in Authentication-Results.
• Every click redirect and open-tracking host.
• Link destinations added by templates, signatures, or calendar tools.
• Plain-text and HTML parts.
• Unsubscribe headers when they apply.
• Differences between the tested message and the live campaign step.

A branded tracking CNAME can resolve correctly while the final message still contains another shared redirect or pixel host. Use the tracking domain checker for the configured host, then inspect the .eml to discover every host the receiver saw.

Follow why authenticated emails still go to spam for the full placement investigation across reputation, tracking, SMTP identity, and recipient-side rules.

8. Check the infrastructure Instantly cannot grade independently

Instantly is the sending platform and its inbox placement test is a first-party seed test. Both provide useful operating evidence. A launch decision can still need an independent read of the surrounding infrastructure.

Check:

• Live public DNS rather than a saved setup state.
• Domain age and current blacklist evidence.
• Tracking-domain DNS, HTTPS, certificate, and redirect behavior.
• PTR, forward-confirmed reverse DNS, HELO, and banner identity for custom SMTP egress.
• Receiver requirements across every sending domain in the workspace.
• Whether a rerun preserved the original failure and verified the fix.

This does not replace Instantly. It answers a different question. Instantly operates campaigns and supplies account, bounce, and placement evidence. OutboundQA checks the external setup and records a Ready, Needs Fix, or Do Not Launch verdict across the workspace. The Instantly alternative page explains where the two evidence classes fit together.

Instantly deliverability troubleshooting checklist

Require evidence in every row before resuming or scaling a campaign.

Area	Evidence	Decision
Campaign state	Selected accounts, active status, schedule, send counts, pause reason	Ready / Needs Fix / Do Not Launch
Account connection	Connected and not paused, daily limit, manual send and receive	Ready / Needs Fix / Do Not Launch
Bounces	Type, SMTP response, sender, recipient provider	Ready / Needs Fix / Do Not Launch
Authentication	Live SPF, DKIM, DMARC, MX, and message alignment	Ready / Needs Fix / Do Not Launch
Warmup and volume	Recent activity, ramp, limits, domain history	Ready / Needs Fix / Do Not Launch
Placement test	Provider-level Inbox, Promotions, Spam, Missing	Evidence only
Message surface	Headers, tracking hosts, links, plain text, unsubscribe	Ready / Needs Fix / Do Not Launch
External infrastructure	Blacklists, tracking HTTPS, SMTP identity, receiver rules	Ready / Needs Fix / Do Not Launch

FAQ

Why is my Instantly campaign not sending emails?

Check whether the campaign has no selected sending accounts, the accounts are paused or disconnected, they hit their daily limit, the slow-ramp setting is holding volume, high-bounce auto-pause fired, or your plan expired. A campaign that did not send is an operations problem, not proof of poor inbox placement. Note that account or setting changes can take 10 to 15 minutes to apply.

Why did Instantly auto-pause my campaign for high bounces?

Instantly’s high-bounce auto-pause is on by default. It pauses a campaign once the bounce rate passes the threshold, 5% by default, after the campaign has sent at least 200 emails. Classify the bounces and fix the cause before resuming. After you resume, that campaign is not auto-paused for high bounces again for 7 days.

Why do Instantly emails go to spam when SPF, DKIM, and DMARC pass?

Authentication proves identity and alignment. Providers can still filter an accepted message using domain and IP reputation, complaint history, sending patterns, message content, tracking hosts, and recipient-side rules. Inspect the received message and compare outcomes by provider.

Does a passing Instantly inbox placement test guarantee inbox placement?

No. An inbox placement test records where a test message landed across its seed mailboxes at that time. It does not guarantee the result for every prospect, provider, corporate gateway, message, or future send.

Should I pause an Instantly campaign with high bounces?

Yes. Pause the affected sending path while you classify the SMTP responses and separate invalid leads from sender-side failures. Continuing to send before the cause is fixed can add more reputation damage and make the evidence harder to read.

Run an independent check before the next send

Start with the free email deliverability checker for one sending domain. It checks observable authentication, routing, reputation, tracking, domain-age, and SMTP identity signals. A passing result removes known infrastructure blockers. It does not guarantee inbox placement.

For a client workspace, preserve the Instantly campaign evidence beside the independent infrastructure verdict and the verified rerun. The result is a troubleshooting record another operator can review instead of a collection of dashboard screenshots.