Email deliverability refers to the ability of your emails to successfully reach your recipients' inboxes, avoiding the spam folder. This guide provides key strategies to enhance deliverability rates when using Mailjet.
Build a High-Quality Email List
Avoid Purchased or Scraped Lists
Always grow your email list organically. Sending emails to purchased or scraped lists results in high bounce rates, complaints, and potential blacklisting. Mailjet strictly prohibits the use of third-party lists. Additionally, using such lists is illegal in many countries.
✓ Action: Do not use any third-party or purchased lists.
Remove Role Accounts
Role accounts (such as info@, contact@, admin@) are typically used by teams or departments rather than individuals. Sending emails to these addresses can lead to high spam reports since these recipients likely never opted in.
✓ Action: Regularly clean your contact lists by removing all role accounts.
Use Double Opt-In
Ensure your subscribers genuinely consent to receive your emails by implementing a double opt-in process. Mailjet’s Subscription Form Builder simplifies verifying email addresses and reduces invalid sign-ups.
Send a confirmation email with a verification link to all new subscribers. Once they confirm, you can safely add their email address to your contact list and send them a welcome message.
Why is Double Opt-In Important?
It confirms the email owner’s desire to receive your communications and prevents fake or mistyped addresses from entering your list.
✓ Action: Implement a double opt-in process for your list-building efforts.
Maintain List Hygiene
👉 Regularly Clean Your Email List
Keep your email list healthy by regularly removing inactive or invalid email addresses. Mailjet’s segmentation and contact management tools make this easy.
Mailjet automatically handles unsubscribes, bounces, and spam complaints, but you should actively remove these addresses from your lists to improve deliverability and engagement rates.
✓ Action: Use Mailjet’s guide to maintain a list of engaged contacts.
👉 Manage Inactive Subscribers
Regularly assess your list for inactive subscribers—those who haven’t opened or clicked your emails in 3-6 months. Inactive contacts reduce your engagement rates and can hurt your sender reputation.
You can either remove inactive subscribers from your lists or send re-engagement emails to win them back.
✓ Action: Identify inactive subscribers regularly and decide whether to remove or re-engage them.
✓ Sunset Policies: Enforce sunset policies to manage inactive subscribers effectively, reducing the likelihood of spam complaints.
👉 Remove Unused Email Addresses
If you haven’t sent emails to a list in several months, you risk higher bounce rates, spam complaints, and hitting spam traps. It’s best to remove unused lists or send a re-confirmation email before re-engaging them.
✓ Action: Remove contact lists older than six months or send a re-confirmation email.
👉 Use Bulk Validations
When working with older, imported contact lists, use Bulk Validations to identify invalid or risky email addresses before sending.
Bulk Validations helps protect your sending domain and IP reputation by improving recipient quality and reducing bounce and suppression events.
✓ Action: Validate contact lists before sending and remove invalid or high-risk addresses.
Collect Consent for Offline Lists
When collecting email addresses offline, such as through business cards or sign-up sheets, always obtain explicit consent before adding them to your mailing list. Proof of consent is required by Mailjet’s Acceptable Use Policy.
✓ Action: Send a confirmation email for all offline-gathered contacts to ensure compliance.
Authenticate Your Emails
Set Up SPF, DKIM, and DMARC
Email authentication protocols like SPF, DKIM, and DMARC are essential for proving the legitimacy of your emails and preventing them from being flagged as fraudulent.
Configuring these records for your custom domain enhances your sender reputation and ensures that your emails are delivered to inboxes, not spam folders.
✓ Action: Follow Mailjet’s step-by-step guide to set up SPF and DKIM records and gain a clear understanding of DMARC to enhance email security and deliverability. Be sure to review the 2024 Gmail and Yahoo updates for optimal deliverability.
Follow Email Content Best Practices
Send Relevant and Engaging Content
Regularly send new and interesting content to your contact lists. Avoid recycling old material and make sure your emails are something subscribers look forward to.
✓ Action: Set a consistent schedule, use fresh content, and always include a visible unsubscribe link.
Maintain a Good Text-to-Image Ratio
Ensure your emails maintain a 70% text to 30% image balance to improve deliverability.
✓ Action: Keep a balanced text-to-image ratio in all your email campaigns.
Subject Line Length
The length of a subject line can impact deliverability, but it primarily affects open rates and engagement, which, in turn, influence deliverability over time. Keep your subject less than 50 characters long.
Here’s how subject line length plays a role
- Visibility in Inboxes: Shorter subject lines (around 40-50 characters) are easier to read and don’t get cut off on mobile devices. Long subject lines can be truncated, which may cause recipients to overlook the email or misunderstand the message.
- Engagement Rates: Shorter, concise subject lines are more likely to grab attention and encourage engagement (opens and clicks), which boosts sender reputation over time and helps with inbox placement.
- Spam Filters: While subject line length itself isn’t a direct factor for spam filters, excessively long or misleading subject lines can raise red flags if combined with other factors (like spammy keywords, all caps, or excessive punctuation).
- Best Practice: Aim for subject lines of 6-10 words or 40-50 characters to balance visibility and clarity. Testing different lengths with A/B testing can help identify what works best for your audience.
Avoid Spammy Language
Stay away from phrases and words like "free," "act now," or "limited time offer," as well as excessive punctuation or caps lock.
Words That Trigger Spam Filters: Avoid These in Your Emails
Spammy words to avoid in email marketing are typically ones that trigger spam filters due to their association with scams, pushy sales tactics, or unsolicited content. Here’s a breakdown of high-risk spammy words across common categories:
Financial
- "Earn", "Discount", "Investment", "Credit", "Million dollars", "Financial freedom"
- These terms often signal get-rich-quick schemes and can immediately flag emails as spam.
Urgency
- "Limited offer", "Act now", "Urgent", "Immediate", "Only a few left"
- Words that push urgency are often associated with scams or pressuring sales tactics.
Marketing and Sales Promotions
- "Free", "Buy now", "Bonus", "Coupon", "Clearance", "Sale"
- Overusing promotional words can result in emails landing in spam because they’re linked to commercial spam and unsolicited promotions.
Health
- "Viagra", "Weight loss", "Supplement", "Herbal", "Cure"
- Health-related words, especially ones tied to pharmaceuticals or medical claims, are heavily flagged.
Personal and Confidential Claims
- "Winner", "Guaranteed", "Private", "Confidential", "Secret"
- These terms can signal scam attempts or phishing, as they imply exclusivity and urgency that seem untrustworthy.
Exaggerated Claims
- "Miracle", "Unbelievable", "Life-changing", "Ultimate", "Sensational"
- Over-the-top words make emails appear unrealistic and can result in automatic filtering.
Suspicious Attachments and Links
- "Download now", "Click here", "See attachment", "Exclusive download"
- Calls to action involving downloads or attachments can seem suspicious, triggering security flags.
The Most Critical Words to Avoid Across All Categories:
- Free
- Earn
- Credit
- Weight loss
- Discount
- Miracle
- Winner
- Urgent
- Act now
- Click here
These words raise red flags with most spam filters. Minimizing their use, or using alternative wording, can help ensure that emails reach the inbox.
✓ Action: Avoid spam-trigger words and unnecessary punctuation in your emails.
Optimize for Mobile
Make sure your emails are mobile-friendly. Mailjet’s responsive templates adjust automatically to different screen sizes.
✓ Action: Use Mailjet’s responsive templates to ensure mobile optimization.
Enhance Engagement with Your Emails
Personalize Your Emails
Personalized emails drive higher engagement rates, which positively impacts deliverability. Mailjet’s dynamic content and personalization tools help you tailor messages based on subscriber data.
✓ Action: Use personalization features to make your emails more relevant to each subscriber.
Segment Your Audience
Use Mailjet’s segmentation tools to create groups based on location, activity, or other factors. This allows you to send more relevant content and improve engagement.
✓ Action: Segment your audience to deliver targeted and relevant emails.
Monitor Open and Click Rates
Mailjet’s analytics help you track how subscribers interact with your emails. Low open rates may indicate deliverability issues or irrelevant content.
✓ Action: Regularly monitor open and click rates to identify potential deliverability issues.
Reactivate Inactive Subscribers
Send re-engagement campaigns to inactive subscribers. Consider removing them from your list to maintain a healthy engagement rate if they remain unresponsive.
✓ Action: Send re-engagement campaigns or remove inactive subscribers from your list.
Test and Monitor Deliverability
Use A/B Testing
Regularly A/B test subject lines, content, and send times to find out what resonates best with your audience. Mailjet’s A/B testing feature can help you optimize your campaigns.
✓ Action: Use A/B testing to optimize your emails for better performance.
Send Emails at Optimal Times
Analyze your past campaigns to find the best times to send emails. Use Mailjet’s scheduling feature to send emails when your subscribers are most active.
✓ Action: Schedule your campaigns to be sent at the optimal times for engagement.
Comply with Email Regulations
Ensure your campaigns comply with laws like GDPR and CAN-SPAM. Always include clear unsubscribe links and company information, and respect your subscribers' privacy. Mailjet’s Subscription Form Builder helps with GDPR-compliant data collection.
✓ Action: Ensure your campaigns comply with email regulations and include necessary legal information.
Conclusion
By following these best practices and leveraging Mailjet’s powerful tools, you can significantly improve your email deliverability, maintain a healthy contact list, and build stronger relationships with your subscribers.
For even more insights, explore our free white paper, which outlines 34 factors that can impact your deliverability.