SKULabs sends several types of transactional emails: shipped notifications to customers, partially shipped notifications, backorder emails, purchase order emails, and low stock alerts. This guide covers the most common reasons these emails fail to send or arrive, and what to do about each one.
Shipped email not sending to customers
First: understand the two email systems
There are two separate email notification systems in SKULabs, both configured under Settings > Stores > (your store) > Shipping defaults and settings > Shipping notifications settings:
SKULabs shipment notification email — emails sent directly by SKULabs to your customer using your configured email template
Channel customer notification email — instructs your sales channel (Shopify, BigCommerce, etc.) to send its own built-in shipping notification
Both are independent. You can have one, both, or neither enabled. If your customers aren't receiving notifications, check which of these is enabled and configured correctly.
How to enable SKULabs shipment notification emails
Go to Settings > Stores and click the edit icon for your store.
Scroll down to Shipping defaults and settings and expand it.
Under Shipping notifications settings, find SKULabs shipment notification email.
Set it to one of:
Never — SKULabs will not send any shipment emails (default for channel-connected stores)
Complete shipments only — SKULabs sends an email only when an order is fully shipped
Partial shipments only — SKULabs sends an email only on partial shipments
Partial and complete shipments — SKULabs sends an email for both
Save the store settings.
How to configure channel notification emails
The Channel customer notification email dropdown controls when SKULabs tells your sales channel to trigger its own notification email:
Never
Complete shipments only
Partial and complete orders
Non-dropshipped orders
Release orders upon scan
If your customers are receiving duplicate shipping emails, it's likely because both SKULabs and the channel are set to send. Set one of them to Never to prevent duplicates.
Manual stores (not connected to a sales channel) always rely on SKULabs to send emails directly. Make sure SKULabs shipment notification email is not set to Never, and that the Shipped e-mail template is configured — see below.
"Missing e-mail template fields" error
Missing e-mail template fields (email / name / subject). Please go to your SKULabs store settings then review the email templates.
The shipped email template for that store hasn't been configured with the required fields. SKULabs needs at least a From E-mail, From E-mail Name, and Subject to send.
Fix:
Go to Settings > Stores and click your store name.
Scroll down and click the Templates panel.
Click the pencil icon next to Shipped e-mail (and/or Partially shipped e-mail if applicable).
Fill in the From E-mail, From E-mail Name, and Subject fields.
Click Save.
Templates are configured per store — you'll need to do this for each store separately.
Shipped email not sending when orders are shipped via the API
If you're using the SKULabs API to mark orders as shipped (via the add_manual_shipment endpoint), customer notification emails are not currently sent automatically through this path. The shipped email is only triggered when an order is shipped through the SKULabs UI (the Ship button, bulk ship, or batch ship).
Workaround: If you're building an integration that ships orders via API and needs to send customer notifications, you can either:
Send the notification email from your own system directly (e.g. via Postmark, SendGrid, etc.) after calling the SKULabs API.
Disable shipped emails in SKULabs store settings and handle all notification emails from your integration.
Contact SKULabs support if you need guidance on the best approach for your workflow.
Customizing email templates
SKULabs has two email template editors — V1 (the classic editor) and V2 (the newer code-based editor). Both are accessible from Settings > Stores > (your store) > Templates.
V1 template editor
The V1 editor is a simple form-based editor. It shows fields for From E-mail, From E-mail Name, Subject, and CC, with a WYSIWYG body editor and a live preview below. This is the default editor for all stores.
At the bottom of the editor, click Toggle advanced options next to the Advanced label to reveal additional settings including a test send option.
V2 template editor
V2 is a more powerful code-based editor with a split-panel layout — HTML/Liquid code on the left, live preview on the right. It supports full template customization using Liquid-style syntax and includes a Template Assistant (Beta) AI bar at the top for generating template changes in natural language.
If your store has been invited to V2, you'll see a blue banner at the top of the V1 editor saying "You have been invited to template editor v2" with an Open Editor link. Click that to launch V2. V2 access is rolling out gradually — if you don't see the banner, contact SKULabs support to request access.
V2 templates use:
{% %}for structural tags (e.g.{% EmailTemplate %},{% EmailShipments %})#{{ }}for output variables (e.g.#{{ customer.name }},#{{ orderNumber }})A Shipped Email Options dropdown at the top for quick configuration
See also: How to use the V2 template editor
Adding a CC address to email templates
You can add a CC address to any email template in SKULabs so that your own inbox receives a copy whenever that email is sent to a customer. This is useful for monitoring outgoing shipment notifications and backorder emails.
Go to Settings > Stores > (your store) > Templates.
Click the pencil icon next to the template you want to edit (e.g. Shipped e-mail, Purchase order e-mail).
Find the CC field and enter the email address(es) you want to receive copies.
Click Save.
If you're not receiving CC copies as expected, contact SKULabs support with the store name, template name, and an example order number.
Error: "Email domain is blocked by SKULabs administrators"
There was an issue sending a shipment notification email to this customer. The "TO" email domain for [email] in Order #[number] is blocked by SKULabs administrators.
SKULabs blocks certain email domains from receiving transactional emails to protect deliverability and prevent emails from being sent to known-invalid, misspelled, or problematic domains.
Common reasons a domain may be blocked:
Misspelled domains — e.g.
gmial.com,hotmaail.com,tahoo.com,iclould.comPlaceholder domains — e.g.
example.com,none.comHigh bounce rate domains — domains that have historically caused delivery failures
Known spam or phishing domains
What to do:
If the customer's email contains a typo, correct it: open the order, click Edit address, fix the email field, and retry.
If you believe the domain is valid and incorrectly blocked, contact SKULabs support with the email address and order number.
For orders where the customer used a placeholder email at checkout (common with guest checkouts), obtain a valid address from the customer and update the order before retrying.
Postmark errors on PO and supplier emails
"Postmark error: You tried to send to a recipient that has been marked as inactive"
Could not send purchase order email to [email] - Postmark error: You tried to send to recipient(s) that have been marked as inactive.
Postmark (SKULabs's email delivery service) has marked this recipient as inactive — usually because a previous email hard-bounced, the address unsubscribed, or the email server repeatedly rejected emails.
What to do:
Verify the supplier's email address is correct. A single typo can cause a hard bounce that permanently suppresses the address.
Contact SKULabs support with the email address. We can check the suppression status in Postmark and remove it if appropriate.
If the supplier changed their email, update it in Settings > Suppliers and retry the PO.
The same suppression issue can affect customer shipped emails. Contact SKULabs support with the customer's email and order number if this occurs.
Email sent but customer says they didn't receive it
If no error appears on the order but the customer says they didn't get the email:
Check the customer's spam/junk folder. Transactional emails sometimes land in spam, especially with Hotmail, Yahoo, and corporate mail servers.
Verify the email address on the order. A single typo (e.g.
.coninstead of.com) will silently fail or bounce.Check if the domain is blocked. If you see the "domain blocked" error on the order, follow the steps above.
Check your email template's From E-mail address. Some mail servers reject emails from unverified senders. Make sure your From E-mail uses a verified domain.
Contact SKULabs support with the order number and customer email. We can check Postmark delivery logs to confirm whether the email was sent, bounced, or blocked.
Not receiving SKULabs system emails (low stock alerts, PO copies, etc.)
If you've stopped receiving emails that used to work:
Check spam and search for emails from
noreply@skulabs.comor your configured From E-mail address.Check your notification settings. Go to Profile > Notification settings and confirm the relevant notifications are enabled.
Check if your address is suppressed. If a previous email bounced, Postmark may have suppressed your address. Contact SKULabs support to check and remove it.
Check your email filters. A rule in your inbox may be archiving or deleting SKULabs emails automatically.
Verifying your email domain for better deliverability
Setting up SPF, DKIM, and DMARC records tells receiving mail servers that SKULabs is authorized to send on behalf of your domain, reducing the chance of emails landing in spam. Contact SKULabs support for the specific DNS records needed — we can provide same-day setup instructions.
Why does Shopify say "SKULabs sent a shipping confirmation email"?
When SKULabs sends a tracking number update to Shopify, Shopify may log this as SKULabs having sent a shipping email. This is a Shopify UI labeling issue — it doesn't necessarily mean SKULabs sent a separate customer email. Whether SKULabs sends its own email depends on your SKULabs shipment notification email setting under Shipping notifications settings.
Frequently asked questions
Can I send a test email from SKULabs?
Yes. Open any email template (Settings > Stores > your store > Templates), then click Toggle advanced options next to the Advanced label at the bottom of the editor to reveal a test send option.
Can I send a shipped email to a customer after the fact?
Yes. Open the order, click the Menu button, and select Send email to manually trigger the shipped notification for that order.
Can SKULabs send emails only for certain SKUs?
Not natively — notifications are configured at the store level, not the SKU level. You can use Shipping rules (Settings > Shipping > Rules) with the action Channel should NOT send email notification to suppress emails based on order criteria, but this suppresses the channel's email rather than SKULabs's own email sending.
Can I send emails after a delay (e.g. a few hours after shipping)?
Not currently. SKULabs sends emails at the moment the shipment is processed. Contact support if delayed sending is important for your workflow.
Can I use my own Postmark account for SKULabs emails?
This is not currently supported as a self-service option. Contact SKULabs support to discuss your specific use case.
Why are my customers getting duplicate shipping emails?
This happens when both SKULabs shipment notification email and Channel customer notification email are enabled at the same time. To stop duplicates, set one of them to Never in your store's Shipping notifications settings.
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