# Common errors

> What to do when emails land in spam, bounce, or an inbox stops working, and when to hand it to a person.

Source: https://docs.maildeck.co/deliverability/common-errors/

**Most problems come down to DNS records, bad addresses, copy or sending too much.** Find what you're seeing in the
tables below. If the answer is "message the team", do it early: pausing a struggling inbox quickly often saves the
domain.

## Domains and DNS

| What you see | Likely cause | What to do |
|---|---|---|
| "DNS records not found" or a record check fails | Records were added recently and haven't spread yet, or one is set wrong | Wait up to 48 hours after setup, then check again with [MXToolbox](https://mxtoolbox.com/). Still failing? Message the team with the domain name. |
| "Multiple SPF records" | The domain has two SPF lines; it may only have one | Message the team. Don't add or delete records yourself, especially during warmup. |
| "DKIM signature not valid" | A DKIM record points to the wrong value | Message the team. DKIM values are unique to each tenant. |
| "Domain reputation low" | Too many bounces or spam complaints from that domain | **Pause all sending from the domain** and message the team. They'll check whether it can recover or should be replaced. |
| Warmup emails bouncing | A DNS setting is wrong (usually SPF or MX) | Message the team with the domain name. |

## Inboxes

| What you see | Likely cause | What to do |
|---|---|---|
| "Authentication failed" when connecting an inbox to your sequencer | Wrong credentials, or the inbox isn't fully set up yet | Check your order on the dashboard. If it's still being set up, wait until it's complete. If it's complete and still failing, message the team. |
| Inboxes don't appear in your sequencer | Setup isn't finished yet | Check the dashboard. Once the order is complete and they're still missing, message the team. |
| "Inbox suspended by Microsoft" | Too much volume, or copy that tripped Microsoft's abuse filters | **Pause every campaign using that inbox** and message the team straight away. Then check your copy against [Writing for Outlook](https://docs.maildeck.co/deliverability/writing-for-outlook/). |
| No warmup activity | The inbox's connection to your sequencer needs fixing | Message the team with the inbox address. |

## Delivery

| What you see | Likely cause | What to do |
|---|---|---|
| Emails landing in spam | Domain reputation, copy, or sending pattern | Work through the checklist below. |
| High bounce rate | Sending to invalid or outdated addresses | Stop the campaign. Verify the list with [EmailShield](https://docs.maildeck.co/leads-verification/emailshield/) before sending again. Aim to keep bounces under 5%. |
| Emails not received at all (not even in spam) | The receiving server is rejecting them | Try a different recipient. If it only happens with one company's addresses, that company may be blocking you; message the team. |
| Replies suddenly drop | Copy has gone stale, list is tired, or a deliverability problem | Refresh the copy and the list first. If replies stay very low, check the spam checklist below. |

### If emails are landing in spam

1. **Check the records.** Use [MXToolbox](https://mxtoolbox.com/) to confirm SPF, DKIM and DMARC all pass.
2. **Turn off tracking.** Disable open tracking and link tracking in your sequencer.
3. **Simplify the copy.** Remove images, links and heavy formatting. On Outlook, keep to about 50 words.
4. **Lower the volume.** Send fewer emails per inbox per day; see [Safe sending limits](https://docs.maildeck.co/deliverability/sending-limits/).
5. **Check blacklists.** The [MXToolbox blacklist check](https://mxtoolbox.com/blacklists.aspx) shows if your domain
   is listed.
6. **Check warmup.** Make sure you didn't start cold sending before the inboxes were ready, and that warmup is still
   running.

> **Caution: When to stop sending from an inbox**
> Pause straight away if bounces go above 5%, you get several spam complaints from the same domain, the inbox suddenly
> lands in spam, or Microsoft or Google sends a throttling or suspension notice. Then message the team.

## When to message a person

Message the team when:

- an inbox is suspended or a domain's reputation drops,
- DNS checks still fail 48 hours after setup,
- warmup emails bounce, land in spam or stop,
- you've worked through the checklist above and still land in spam,
- anything is about a specific order, a refund, a cancellation or billing.

**Where:** your private Slack channel with the team (it opens with your first order), or the chat bubble in the
bottom-right corner of the app. You can also email help@maildeck.co. Maya, the AI guide in the app, can help with
general questions any time.

**What to include**, so the team can start straight away:

- the domain or inbox address,
- the exact error message (a screenshot is fine),
- what you were doing when it happened.

> **Danger: Never send passwords or API keys in chat**
> The team won't ask for them in a message. If something needs new credentials, they'll tell you how to update them
> safely.

## Related

  - [Getting help](https://docs.maildeck.co/support/getting-help/): All the ways to reach us.
  - [SPF, DKIM and DMARC](https://docs.maildeck.co/domains-dns/spf-dkim-dmarc/): What the records do.
  - [Safe sending limits](https://docs.maildeck.co/deliverability/sending-limits/): Daily numbers per inbox type.
  - [Maya](https://docs.maildeck.co/support/maya/): Your AI guide in the app.