Email Deliverability for Space Companies: SPF, DKIM, DMARC

TL;DR: Email deliverability decides whether your sales follow-ups, proposals and newsletters reach an inbox or vanish into spam. For a space company, the fundamentals are authenticating your domain with SPF, DKIM and DMARC, meeting Gmail and Yahoo sender requirements, keeping spam complaints low, sending marketing email from a separate subdomain and only emailing people who expect to hear from you. Set it up once, check it after any tool change and monitor reports so a misconfiguration doesn't quietly cost you deals.

Key takeaways

• Authenticate every domain and tool that sends email for you.
• Gmail and Yahoo set clear rules, and bulk senders face stricter ones.
• Protect your main domain by sending marketing email from a subdomain.
• List quality and relevance matter as much as technical setup.

Why does email deliverability matter for space companies?

Space sales run on email: follow-ups after trade shows, technical documents, proposals, contract discussions and nurture sequences. If those emails land in spam, deals stall and nobody knows why.

Deliverability problems are often invisible. Your CRM shows "sent," but the buyer never saw it. A few hours of setup prevents months of silent losses.

What are SPF, DKIM and DMARC?

They're the three standards that prove your email is really from you:

Standard	What it does	Simple analogy
SPF (Sender Policy Framework)	Lists the servers allowed to send email for your domain	A guest list
DKIM (DomainKeys Identified Mail)	Adds a digital signature that proves the message wasn't altered	A tamper-evident seal
DMARC	Tells receivers what to do when SPF or DKIM checks fail, and sends you reports	Instructions to the doorman

According to DMARC.org, DMARC builds on both DKIM and SPF, and DMARC policies are published in DNS as text records that tell receivers what to do with mail that isn't aligned. A sender testing its configuration can use "quarantine" instead of "reject."

What do Gmail and Yahoo require from senders?

Google's email sender guidelines require all senders to Gmail accounts to set up SPF or DKIM, keep spam rates reported in Postmaster Tools below 0.3% and meet other technical requirements. Senders of more than 5,000 messages per day to Gmail accounts must also set up SPF, DKIM and DMARC, align the From: domain with SPF or DKIM and support one-click unsubscribe for marketing and subscribed messages.

Yahoo's sender best practices set similar rules: all senders should implement SPF or DKIM and keep spam rates below 0.3%, while bulk senders need SPF and DKIM, a valid DMARC policy of at least p=none and a functioning one-click unsubscribe.

Most space companies won't hit bulk volumes, but meeting the bulk standard anyway is the safest approach.

How do you set up email deliverability step by step?

1. List every tool that sends email for you: Google Workspace or Microsoft 365, your CRM, marketing platform, support desk, proposal software and website forms.
2. Set up SPF. Publish one SPF record that includes every legitimate sender. Only one SPF record per domain is allowed.
3. Turn on DKIM in each sending tool and publish its DNS records.
4. Publish a DMARC record starting at p=none with a reporting address (rua), so you can see who sends as your domain.
5. Review DMARC reports for a few weeks and fix any legitimate senders that fail.
6. Tighten the policy to quarantine, then reject, once everything legitimate passes.
7. Use a subdomain for marketing, such as news.yourcompany.com, so a marketing issue doesn't hurt sales email from your main domain.

How do you keep a good sender reputation?

Technical setup gets you through the door. Behavior keeps you there:

• Email people who expect it. Don't buy lists or add badge scans to newsletters without consent.
• Make opting out easy. A visible unsubscribe link reduces spam complaints.
• Clean your list. Remove bounces and long-term non-openers.
• Send relevant content. Segment by role and interest.
• Warm up new domains gradually rather than sending large volumes on day one.
• Keep sales emails personal. Plain text from a real person tends to perform well for one-to-one follow-up.

Our trade show follow-up email templates are a good example of personal emails that respect these rules.

How do you test email deliverability?

• Check your DNS records with a free SPF, DKIM and DMARC lookup tool.
• Send test emails to Gmail and Outlook accounts and check message headers for "pass" results.
• Use Google Postmaster Tools to monitor spam rate and reputation if you send to many Gmail users.
• Watch reply and open trends in your CRM. A sudden drop often signals a problem.

How does deliverability connect to your CRM?

Your CRM often sends the most important emails: automated follow-ups, nurture sequences and notifications. Make sure it's authenticated on your domain, not sending from a generic shared domain. Our space startup CRM guide covers setup, and our space industry CRM automation service handles authentication as part of the build. If you're new to email, start with our guide to email marketing for space companies.

For the strategy behind the emails, see our space marketing guide and space startup marketing playbook.

What does an email deliverability checklist look like?

• SPF record published, with every sending tool included.
• DKIM enabled in each sending tool.
• DMARC record published with a reporting address.
• Marketing email sent from a subdomain.
• One-click unsubscribe and a visible unsubscribe link in marketing emails.
• Spam complaint rate monitored and kept low.
• Bounces removed regularly.
• Setup rechecked after adding any new email tool.

What should you do if your emails are already landing in spam?

Work through the causes in order:

1. Check authentication. Look at message headers for SPF, DKIM and DMARC results and fix any failures.
2. Check recent changes. A new CRM, form tool or domain often breaks authentication.
3. Pause bulk sends while you investigate, and keep one-to-one sales email going from a properly authenticated mailbox.
4. Clean the list. Remove bounces, unengaged contacts and anyone who didn't opt in.
5. Restart gradually, starting with your most engaged contacts.

Recovery takes time, so fix the cause first rather than sending more email to compensate.

What email deliverability mistakes do space companies make?

• Adding a new tool without updating SPF and DKIM.
• Multiple SPF records, which breaks SPF.
• Jumping straight to p=reject before checking reports, which can block legitimate email.
• Sending marketing email from the main domain.
• Buying lists, which drives complaints and bounces.

Frequently asked questions

What is email deliverability?

Email deliverability is the ability of your emails to reach recipients' inboxes rather than spam folders or being blocked. It depends on authentication, sender reputation and content relevance.

Do I need SPF, DKIM and DMARC?

Yes. Gmail requires all senders to set up SPF or DKIM, and bulk senders need all three. Setting up all three protects your domain and improves inbox placement.

What spam rate do Gmail and Yahoo allow?

Both Google and Yahoo say to keep spam rates below 0.3%.

What DMARC policy should I start with?

Start with p=none and a reporting address, review reports, fix legitimate senders, then move to quarantine and reject.

Should I send marketing email from a subdomain?

It's a good practice. A subdomain separates marketing reputation from your main domain, protecting one-to-one sales email.

Want this built for your space company?

Book a free Growth Audit. On a free 20-minute call, we look at your marketing and sales, find the step that is holding growth back and show you what we would do first.

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