Best practices for improving email deliverability

Follow these best practices to ensure that you have strong email deliverability metrics

Improving email deliverability to all of your contacts, including those provided by Opensend,  is important to maintain a positive reputation and to ensure that your emails land in the inbox instead of the spam folder. Here are some easy steps to make sure your emails reach your contacts:

  1. Use a professional domain: Use a custom subdomain associated with your business or organization. A custom domain lends credibility to your emails.

    A branded sending domain allows you to send emails that appear to be coming from your brand and allows you to have better overall control of your sender reputation. If you don't use a custom domain, the sender information at the top of an email message will show its coming from your email marketing platform  (i.e., “sent on behalf of '' or “via klaviyomail.com”).
  2. Authenticate your domain: Implement SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) records to authenticate your domain. This helps prevent your emails from being flagged as spam.

  3. Warm-up your domain: Gradually increase the volume of emails you send from your domain to build a positive sender reputation. Start with a small number of emails and gradually increase the volume over time. Warming is the period of time in which you are establishing a reputation as a legitimate or “good” email sender. There are tools available which can be used to warmup your email sender in an automated way, hence we suggest utilizing an email sender warmup platform.

  4. Maintain a clean list: Regularly clean your email list by removing invalid or bounced email addresses. High bounce rates can negatively impact your sender reputation. Use the Opensend Revive service to provide up-to-date email addresses for your subscribers where the existing email in your system has started bouncing / become undeliverable.

  5. Avoid spam words: Avoid generic or spammy-sounding email subject lines and content. There are a number of "Email spam test" tools available which can be utilized to check for common spam words in your email content.

  6. Clearly identify yourself: Make sure your sender name and email address clearly identify who you are and the purpose of the email. Avoid misleading or deceptive sender information.

  7. Provide an unsubscribe option: Include a clear and easy-to-find unsubscribe link in your emails to give recipients the option to opt out. This is not only a best practice but also a legal requirement in many jurisdictions.

  8. Send high-quality content: Ensure that the content of your email flows is relevant and valuable to the recipients. Low engagement rates can negatively impact your reputation.

  9. Manage email frequency: Avoid sending too many emails to the same recipients in a short period. Space out your email campaigns to prevent recipients from flagging your emails as spam. You can find more details on Opensend suggested best practices to engage with contacts here.

  10. Test and optimize: Continuously test different elements of your email flows, such as subject lines, and content to determine what resonates best with your audience and improves open and response rates.

Here are the detailed guidelines on email deliverability improvement from a few of the platforms Opensend Integrates with; if you use another provider they likely have similar guidelines:


Remember that the success of email flows to Opensend contacts not only depends on the sender email setup but also on the quality of your messaging and targeting. Always aim to provide value to your recipients and build a positive reputation over time. 

If you are following all the best practices and still running into issues like high spam rates, please contact your Opensend customer success manager or submit a ticket with our support team here. We can review your setup and Opensend configuration for potential optimizations to increase your deliverability rates.