To keep your nonprofit’s emails out of spam, focus on three key areas: clean, permission-based contact lists, balanced and personalized email content, and consistent sending habits. This guide shows you how to improve deliverability, protect your sender reputation, and build stronger supporter engagement.
Email deliverability determines whether your messages reach inboxes or get filtered as spam.
For nonprofits, this is critical — your donors, members, and supporters can’t take action if they never see your message. Deliverability is not just a technical issue; it’s a matter of trust.
Email providers like Gmail and Outlook evaluate how trustworthy your organization appears as a sender. That trust is built over time — through consistent, transparent communication with real, engaged recipients. When your emails are welcomed, opened, and interacted with, providers learn that your organization sends legitimate, wanted messages.
If, however, your sends are inconsistent, your list includes outdated contacts, or engagement is low, providers start to question that trust — often routing your emails to spam or promotions tabs.
In other words, strong deliverability is built on the same foundation as strong relationships: permission, consistency, and respect for your audience.
Your list is your foundation for trust — and your best tool for sustainable engagement.
Only email people who have explicitly opted in — donors, event attendees, or newsletter subscribers.
Remove or re-engage contacts who haven’t opened or clicked in 6–12 months.
Merge duplicates and ensure first names and email addresses are accurate.
Create categories like:
Event Updates
Fundraising Campaigns
Volunteer Opportunities
News and Impact Stories
This helps you respect supporter preferences and send more relevant content.
(In HubSpot, you can manage this through Subscription Types or Contact Properties.)
Use tools like HubSpot’s graymail filter to prevent sending to disengaged contacts. This protects your sender reputation and improves inbox placement.
Before switching to a new platform, review your old data:
Average open and click rates
Bounce and unsubscribe rates
Sending frequency
This provides a performance baseline to measure future success.
Your content plays a major role in deliverability — both in how providers score your email and how supporters respond.
Avoid overused terms like urgent, free, reschedule, or shutdown, which can trigger filters.
Use about 60% text and 40% images.
Start your email with text (for example, “Hi [First Name],”) before banners or photos.
Most platforms, including HubSpot, generate this automatically — it improves accessibility and credibility.
Add a human touch. Personalized greetings and conversational subject lines signal trust and authenticity.
For urgent updates (like event postponements), use plain-text emails — they appear authentic and bypass some filters.
Keep image-heavy designs on landing pages and link to them.
Make sure your subject, preview, and body text align for clarity and trust.
Use A/B testing to experiment with subject lines, send times, or even message length and design. Test one variable at a time to understand what performs best.
Consistency is one of the biggest factors in deliverability. Email providers track your domain’s behavior — and sudden volume changes can raise flags.
If your list is 20,000+ contacts, start small (10–15K per day) and scale gradually.
In HubSpot, Send in Batches automates this process; otherwise, segment your lists and schedule manually.
Avoid sending 2,000 emails one week and 60,000 the next. Inbox providers track your sending frequency — and sudden spikes look suspicious.
Start with supporters who’ve opened or clicked in the last 90 days. As your reputation grows, include less-active segments.
Before major sends, verify your domain setup:
SPF, DKIM, and DMARC are correctly configured
Bounce <2%, spam <0.1%, unsubscribes <1%
Use a branded domain like info@yourorganization.org
Email providers like Gmail and Outlook maintain a baseline of your domain’s sending behavior.
They monitor:
Volume & Frequency: how many emails you typically send and when.
Engagement: whether people open, click, or report as spam.
Bounce Rates: the number of invalid addresses.
Spam Trap Hits: whether your list includes trap emails.
If your domain usually sends 500 emails a day and suddenly sends 25,000 to Gmail users, Gmail flags it as suspicious — even if your list is legitimate.
💡 Tip: Each provider only evaluates its own users. A large Gmail send won’t affect Outlook directly, but both build separate reputations for your domain.
Even the best lists decay over time. Keeping it clean maintains both deliverability and donor trust.
Pause large sends when engagement drops.
Send friendly re-engagement emails inviting people to confirm preferences.
Offer options like “Send me updates about events only.”
Suppress or remove inactive contacts after repeated non-engagement.
Reconfirm preferences annually or after major data imports.
Review unsubscribed and non-marketing contacts regularly.
Create separate re-engagement workflows to avoid over-sending.
Subject: Schedule Update: Event Postponed
Hi [First Name],
Due to unforeseen circumstances, the event originally scheduled for [Date] has been postponed.
We’re working to confirm a new date and will follow up as soon as details are available.
Thank you for your continued support,
— The [Organization Name] Team
If you have questions, just reply to this message.
| Area | Action | Why It Matters |
|---|---|---|
| Contact List | Send only to opted-in, engaged supporters | Protects sender reputation |
| Subscription Types | Organize by purpose | Improves compliance and clarity |
| Content | Keep text-rich and balanced | Avoids spam filters |
| Personalization | Add names and conversational tone | Boosts engagement |
| Sending Strategy | Use batching or segmentation | Prevents sudden spikes |
| Technical Setup | Verify SPF/DKIM/DMARC | Builds domain trust |
| Benchmarking | Compare to past results | Measures success accurately |
Your nonprofit’s mission deserves to be seen.
By focusing on clean data, authentic communication, and consistent sending habits, your organization can:
Reach more inboxes and supporters
Strengthen relationships with donors and members
Build trust and long-term engagement
Whether you’re using HubSpot, Mailchimp, or another email platform, these best practices will help your nonprofit send with confidence — and ensure your impact reaches the people who believe in your work most.