This guide answers common email channel questions about deliverability, test emails, image display, sender address setup, mobile rendering, HTML templates, and email customization.
Deliverability & Spam Issues
Why are my emails landing in spam folders instead of the inbox?
Emails land in spam for these main reasons:
Missing domain authentication: Set up SPF, DKIM, and DMARC records for your custom sender domain. Go to Store Settings → Domains to verify setup. Learn more about email authentication.
Using free sender addresses: Use a custom sender like [email protected] instead of Gmail, Yahoo, or Outlook. Free provider addresses are often rejected or filtered by mailbox providers.
Low engagement: If contacts consistently ignore your emails, future sends are more likely to land in spam. Send only to engaged subscribers (opened emails in the last 30 days) and clean your list regularly.
Skipping domain warm-up: After setting up a custom domain, gradually increase sending volume (25–35% per campaign) to build sender reputation. Start with your most engaged contacts (opened emails in the last 30 days) and increase volume by 25–35% per campaign.
Why aren't subscribers receiving my emails?
Check these common causes:
Contacts are not subscribed to Email: Only subscribed contacts receive campaigns. Check their subscription status in Audience → Contacts. Learn more about contact statuses.
Emails are landing in spam: Ask recipients to check spam, junk, and promotions folders. If emails consistently land in spam, review domain authentication and sender reputation.
Email sending limits exceeded: Check your plan's monthly email limit in Store Settings → Pricing and usage. If you've reached your limit, emails won't send until the next billing period. Learn more about pricing plans.
Sender domain verified: Go to Store Settings → Domains and verify your sender domain.
Test Emails
Why am I not receiving test emails?
Test emails may not arrive for several reasons:
Check your spam, junk, and promotions folders – test emails often land there because the subject line includes "[Preview]".
Avoid sending from and to the same domain (e.g., sender: [email protected], test: [email protected]). Use a different domain like Gmail or Outlook for test recipients. Some email providers block delivery when the sender domain matches the recipient domain.
Check your plan's daily test email limit: Free (100/day with 50 per 3-hour window), Standard (unlimited), Pro (unlimited), Automations (50/day for all plans). If you've hit your limit, use the Preview feature instead. Learn more about test email limits.
Why do images look broken or missing in test emails?
Test emails use temporary image links that may not display correctly, especially in Gmail or Outlook Web. This doesn't reflect how your real campaign will appear.
To preview images accurately: Send your campaign to a test segment with real subscribers instead of using the test email feature.
Why don't dynamic fields (personalization, discount codes, product picks) appear in test emails?
Test emails and previews don't populate dynamic content like discount codes, contact names, or live links. This is expected behavior.
To see exactly how your campaign will look: Create a segment with only your email address and send the campaign to that segment as a live send.
Image Display Issues
Why are product images not showing or appearing broken in my emails?
Broken images have three main causes:
WebP format: If you use WooCommerce or BigCommerce, your images may be in WebP format. Gmail converts these and can cause distortion or red/pink borders. Replace WebP images in your store with JPG or PNG. Changes sync automatically to Omnisend. Learn more about WebP troubleshooting.
Email client blocking: Many email clients block images by default. Add descriptive alt text to all images so recipients see helpful text when images are blocked. This also improves accessibility.
Test email limitations: Test emails use temporary image links that may not display correctly in Gmail or Outlook Web. Send to a test segment for accurate image previews.
Mobile Rendering
Why does my email look fine in the editor but terrible on mobile?
The editor preview may not perfectly reflect how your email appears in real inboxes. Email clients handle mobile rendering differently.
To fix:
Use Display Settings to show/hide content on mobile vs. desktop: Click any content item → Layout → Display settings → choose "Mobile devices only" or "Desktop devices only".
Set minimum font sizes: 13pt for body text, 20pt for titles on mobile.
Always send to a test segment and view on actual mobile devices (iPhone, Android) before sending to your full list. Learn more about preview and testing.
Note: If you stack two content items and want different visibility settings, you must configure each item separately; changing one won't automatically update the other. Learn more about Mobile Stacking.
Why is my email text extremely small on mobile?
The text size may be too small, or the email doesn't have proper mobile optimization. Check:
Font size is set to at least 13pt for body text on mobile
Content blocks are set to "Show on all devices" (or "Mobile devices only" if you want separate mobile content)
You're testing on real devices, not just the editor preview
💡 Tip: Always send a test campaign to yourself and view it on your phone before sending to your full list. Learn more about preview and testing.
Sender Address & Verification
How do I verify my sender email address?
Go to Store Settings → Email Addresses → Click Add email address → Enter your email → Click Send verification email. Check your inbox (including spam/promotions folders) for the verification link and click it to confirm.
If you don't receive the verification email:
Check your spam and promotions folders.
Wait a few minutes – delivery times vary by email provider.
Contact our Support Team if the email doesn't arrive within 10 minutes.
Why can't I use my personal Gmail or Yahoo address as the sender?
Using free email providers (Gmail, Yahoo, Outlook) as your sender address harms deliverability. Mailbox providers often reject or filter emails sent from free domains.
Use a custom sender address like [email protected] or [email protected] instead. Set up your custom domain in Store Settings → Domains to improve deliverability. Learn how to set up your email domain.
Formatting & Layout
How do I clear formatting issues in my email text?
If text copied from Word, Canva, or another editor causes saving errors or appears with unexpected formatting:
Click Go to element in the error message (if shown);
Select the affected text;
Click Clear formatting in the text toolbar.
Note: If your browser uses a translation tool (e.g., English to French), these tools can introduce hidden formatting that doesn't clear properly. Switch the page back to the original language and try clearing formatting again.
Can I control spacing (padding) between content blocks?
Yes. Click any content block → Layout → adjust Top padding and Bottom padding values.
💡 Tip: Use consistent padding values (e.g., 20px between all blocks) to create a clean, professional look.
HTML & Custom Templates
How do I import a custom HTML email template?
You have two options:
Option 1 – HTML block in the email builder:
Open the email builder → Add Elements → drag the HTML block into your email
Click the HTML block → paste your HTML code
Remove any
<!DOCTYPE>,<head>, and<body>tags—only body content is supported
Option 2 – Import full template:
Go to Store Settings → Saved Templates → Import Template → Paste in code.
Paste your cleaned HTML (without
<!DOCTYPE>or<head>tags).Click Save, and your template will be available for campaigns and automations.
Important: Unsupported tags include <iframe>, <script>, <div>, and <font>. Use inline CSS for styling. All image URLs must start with https:// and be publicly accessible. Learn more about HTML email basics.
Why does my HTML block keep disappearing or won't save?
Your code contains unsupported tags or encoding issues.
To fix:
Copy your HTML and paste it into htmlcorrector.com, then paste the cleaned version back into Omnisend.
Check that you haven't removed required
<p></p>wrapper tags – they're needed for validation even if empty.
Unsupported tags that cause errors: <iframe>, <script>, <div>, <font>, <video>, <audio>, <object>, <embed>.
Why does my email look different in Outlook?
Outlook (especially on Windows) uses the Microsoft Word rendering engine, which has limited HTML/CSS support. To ensure compatibility:
Keep email width at 600px (max 650px).
Use simple table-based layouts (single column).
Avoid background images, border-radius, box-shadow, and flexbox.
Use inline CSS only (no
<style>blocks).Always test in real Outlook inboxes before sending.
Scheduling & Sending
Why did my timezone-based campaign send immediately instead of at the scheduled time?
This happens when you schedule very close to the current time (e.g., 2 minutes ahead) and some contacts have missing timezone data. Omnisend defaults to your account's timezone, and if the scheduled time has already passed for your account's timezone, those emails are sent immediately.
To avoid this: Schedule at least 1–2 hours ahead for timezone-based sends.
Note: Timezone data comes from the contact signup location (IP address) or last activity tracking. If many contacts have unknown time zones, consider setting your account default timezone closer to your customer base (e.g., EST or PST for US audiences).
Footer & Unsubscribe Links
How do I change the color or position of the unsubscribe link in my email footer?
You have specific options with the default footer block:
Color: Click the footer block → use the right panel to adjust link color
Text wording: Go to Store Settings → Language & Translations to change the default text
Position: Use the personalization menu in the email editor to insert the unsubscribe link anywhere in your email (e.g., inside a button or different text block)
Templates & Saved Designs
How do I save an email design as a template?
After designing your email in the Email Builder, click the three-dot menu (top-right) → Save as template → give it a name → Save.
Your template will be available for future campaigns and automations in Store Settings → Saved Templates.
Why can't I find my saved template?
Check that you're looking in the correct location:
Go to Store Settings → Saved Templates to view all saved templates
When creating a new campaign, click Choose template and look under "My Saved Templates"
If your template still doesn't appear, it may not have been saved correctly. Try saving it again.
Tracking & Links
Why don't UTM parameters appear in test emails?
This is expected behavior. Test emails don't populate UTM tracking parameters. UTM parameters are only added to live campaign sends.
To verify UTM parameters work: Send a live campaign to a test segment and click the links to confirm tracking parameters appear in your analytics tool.
Plan Limits & Restrictions
Can I send my Free plan campaign to 500 contacts?
No. The Free plan limits each campaign to 250 recipients. If you try to send to 500 contacts, you'll be asked to upgrade your plan.
You can upload unlimited contacts on the Free plan, but the per-campaign sending limit is 250.
To send to 500 contacts in one campaign, upgrade to the Standard plan (up to 500 recipients per campaign, 6,000 emails/month) or Pro plan (up to 2,500 recipients per campaign, unlimited emails). Learn more about pricing plans.
What happens if I reach my monthly email sending limit?
If you reach your plan's monthly email limit, you cannot send additional campaigns until the next billing period. Scheduled campaigns will fail to send.
To check your usage: Go to Store Settings → Pricing and usage.
To increase your limit: Upgrade your plan. Learn more about pricing plans.
If you didn't find the answer to your question, reach out to our Support Team via in-app chat or at [email protected].