The SaaS Founder's Guide to Email Deliverability

The SaaS Founder's Guide to Email Deliverability

Key Facts

• Direct answer: The direct answer is that email deliverability requires three DNS records (SPF, DKIM, DMARC), a reputable email service provider, and good sending practices (no spam content, consistent sending volume). For more on SaaS operations, see our article on how to handle SaaS user onboarding without losing customers .

• The Three DNS Records: SPF is a DNS record that lists the email servers authorized to send email on behalf of your domain.

• Choose a Reputable Email Provider: Do not send emails from your own server (e.g., via nodemailer with SMTP).

• Sending Practices: Even with SPF, DKIM, and DMARC, poor sending practices can land your emails in spam.

• Transactional vs Marketing Email: Different types of email have different deliverability requirements.

If your SaaS sends emails (verification, password reset, welcome, billing) and they land in the spam folder, your customers miss critical messages. They cannot verify their account, they cannot reset their password, and they cannot receive their invoice. Email deliverability is not just a technical concern — it is a customer experience and revenue issue. This article is the founder's guide to ensuring your emails reach the inbox.

The direct answer is that email deliverability requires three DNS records (SPF, DKIM, DMARC), a reputable email service provider, and good sending practices (no spam content, consistent sending volume). For more on SaaS operations, see our article on how to handle SaaS user onboarding without losing customers.

The Three DNS Records

SPF (Sender Policy Framework)

SPF is a DNS record that lists the email servers authorized to send email on behalf of your domain. Without SPF, email providers (Gmail, Outlook) might reject your emails because they cannot verify the sender.

How to set up SPF:

Add a TXT record to your DNS:

Type: TXT
Name: @ (or myapp.com)
Value: v=spf1 include:_spf.google.com include:sendgrid.net ~all

The include statements list the email providers authorized to send email for your domain. Replace sendgrid.net with your actual email provider (e.g., resend.com, postmarkapp.com).

DKIM (DomainKeys Identified Mail)

DKIM is a DNS record that provides a cryptographic signature for your emails. Without DKIM, email providers cannot verify that the email was not tampered with in transit.

How to set up DKIM:

Your email provider (Resend, SendGrid, Postmark) will provide a DKIM record. Add it as a TXT record to your DNS:

Type: TXT
Name: [provider-specific]._domainkey.myapp.com
Value: [provider-specific DKIM value]

DMARC (Domain-based Message Authentication, Reporting, and Conformance)

DMARC is a DNS record that tells email providers what to do if an email fails SPF or DKIM verification. Without DMARC, email providers might accept spoofed emails (from attackers pretending to be you).

How to set up DMARC:

Add a TXT record to your DNS:

Type: TXT
Name: _dmarc.myapp.com
Value: v=DMARC1; p=quarantine; rua=mailto:[email protected]; pct=100

• p=quarantine tells email providers to send failing emails to the spam folder.
• p=reject tells email providers to reject failing emails entirely (use this once you are confident SPF and DKIM are working).
• rua=mailto:[email protected] sends reports to this email address.

Choose a Reputable Email Provider

Do not send emails from your own server (e.g., via nodemailer with SMTP). Use a reputable email service provider:

• Resend. Developer-friendly, generous free tier (3,000 emails/month), good deliverability.
• Postmark. Focused on transactional email, excellent deliverability, higher cost.
• SendGrid. Popular, good features, larger free tier (100 emails/day).

These providers maintain good sender reputations, handle bounces and complaints, and provide DKIM signing automatically.

For more on background jobs (including email sending), see our article on the SaaS founder's guide to background jobs.

Sending Practices

Even with SPF, DKIM, and DMARC, poor sending practices can land your emails in spam:

• Do not send spam content. Avoid spam-trigger words (e.g., "FREE," "CLICK HERE," "ACT NOW"), excessive capitalization, and too many links.

• Include a clear unsubscribe link. For marketing emails, include a one-click unsubscribe link. This is required by law (CAN-SPAM, GDPR).

• Send consistently. Do not send 10,000 emails one day and 0 the next. Ramp up gradually.

• Monitor bounces and complaints. If your bounce rate exceeds 5 percent or your complaint rate exceeds 0.1 percent, email providers might start sending your emails to spam. Remove bounced addresses from your list.

• Use a custom domain. Do not send from @gmail.com or @yahoo.com. Send from @myapp.com (which requires SPF, DKIM, and DMARC on your domain).

Transactional vs Marketing Email

Different types of email have different deliverability requirements:

• Transactional email (verification, password reset, billing). These are sent to users who expect them, so deliverability is high. Use a transactional email provider (Resend, Postmark).

• Marketing email (newsletter, promotions). These are sent to users who might not expect them, so deliverability is lower. Use a marketing email provider (Mailchimp, ConvertKit) and ensure users have opted in.

Do not mix transactional and marketing email in the same sending domain. Use separate subdomains (e.g., mail.myapp.com for marketing, app.myapp.com for transactional) to protect transactional deliverability.

Common Pitfalls and Troubleshooting

The first pitfall is not setting up SPF, DKIM, and DMARC. Without these records, email providers cannot verify your emails, which means they go to spam. The fix is to set up all three records.

The second pitfall is using a free email provider (Gmail, Yahoo) for sending. Free email providers are not designed for SaaS email, and their deliverability is poor. The fix is to use a reputable email service provider.

The third pitfall is sending from your own server. Self-hosted email has poor deliverability because the server's IP address does not have a good sender reputation. The fix is to use an email service provider.

The fourth pitfall is not monitoring bounces and complaints. If your bounce rate is high, email providers will send your emails to spam. The fix is to monitor bounces and remove bounced addresses.

The fifth pitfall is mixing transactional and marketing email. If marketing email gets flagged as spam, it can affect transactional email deliverability. The fix is to use separate subdomains.

Conclusion: Set Up DNS, Use a Provider, Monitor

Email deliverability is a customer experience and revenue issue. By setting up SPF, DKIM, and DMARC, using a reputable email provider, and following good sending practices, you can ensure your emails reach the inbox. Do not let your verification, password reset, and billing emails land in spam — set up the DNS records and use a provider before launching.

Ready to improve your email deliverability? Set up SPF, DKIM, and DMARC on your domain, switch to a reputable email provider, and test your deliverability. For more, see how to handle SaaS user onboarding and the SaaS founder's guide to background jobs. Explore our free developer tools to speed up your workflow.