> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://help.close.com/technical-support/email-deliverability/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://help.close.com/_mcp/server. # Email Deliverability > Improve email deliverability from Close. Avoid spam filters, follow sending best practices, and set up SPF, DKIM, and DMARC for your domain. Close relies on your email server for sending emails, meaning it follows the same guidelines and limitations as your provider. Mailbox providers use rules to ensure users receive relevant and desirable emails. By following email best practices, you can improve your chances of reaching your audience and maintaining a healthy domain reputation. > **Learn some tips and tricks for sending sales emails and getting responses** > > * [Email Deliverability](https://blog.close.com/improve-email-deliverability) > * [Cold Email Response Rates](https://blog.close.com/cold-email-response-rates) > * [Email Subject Lines](https://blog.close.com/subject-lines) Your email deliverability will be hugely impacted by a few factors. Most notably, these include your domain reputation, the type of content you are putting out, how many people mark your emails as spam, and if a lot of your emails are bouncing. While this is a topic that is constantly changing, here are some common things you can do to help avoid being flagged as spam. ## Avoid Spam Filters * **More is less.** Avoid buying email lists of potential leads. Only contact leads who have indicated an interest in your product and have provided their email address willingly. Purchasing contact lists with fake or disinterested email addresses can damage your domain reputation. This makes it harder for your emails to reach the inboxes of genuinely interested recipients and increases the risk of being marked as spam. * **Focus on clarity.** There are no magic words or formats to avoid. Instead, focus on sending professional, conversational messages that feel personal and relevant. Most email servers do analytics on the contents of incoming emails before deciding if they should land in the main inbox, a secondary inbox (such as Promotions or Updates), or be marked as spam. The chance of your target actually seeing the message drops dramatically if the message ends up anywhere other than the main inbox, so avoid high-pressure sales tactics. Personalized messages stand out more and increase engagement. * **Include an unsubscribe link in your emails.** An ideal location for an [unsubscribe link](/feature-guide/emailing/managing-unsubscribe-requests) is in your email signature and will protect your sender reputation. Close automatically adds the opt-out link to emails sent via Connected Accounts, allowing recipients to unsubscribe rather than mark your emails as spam. This can be set automatically in **Settings > Email > Unsubscribe Link**. * **Keep your list clean.** If you receive permanent bounce messages or unsubscribe requests, don't keep sending emails to these addresses. When it comes to bulk emails, [Close will automatically filter out any leads who have officially unsubscribed](/feature-guide/emailing/managing-unsubscribe-requests#from-the-leads-perspective), but it's possible to send those leads manual emails. Consider avoiding this. * **Be consistent.** Avoid making sudden huge changes to sending volume, and warm-up any new domain before sending a larger amount of marketing emails. Give it at least 4 weeks of warm up time and ramp up your sending volume in that period each week. * **A/B Test Your Messaging.** Use A/B testing in Close to evaluate which email versions resonate best with your audience. Set up different versions of email templates and measure their performance under the [Sent Email Report](/feature-guide/reports/sent-email-report). ## Technical Aspects * Review your SPF record + IP reputation. If you are using a 3rd party sending service such as SendGrid or Mailgun, account for that in your SPF records. You can use [Google's MX Record toolbox](https://toolbox.googleapps.com/apps/checkmx) for this. * Make sure your domain has [DKIM](https://support.google.com/a/answer/174124?hl=en) enabled. * While not as vital as having proper SPF and DKIM records, [setting up a DMARC policy](https://support.google.com/a/answer/2466580) is also a good idea. * If you are still running into deliverability issues, try disabling the [Close application open tracking pixel](/v1/docs/emailing#tracking-email-opens). Some email servers identify hidden pixel images and prevent those emails from being delivered. * Avoid using novelty domain extensions. Stick to trusted ones like .com, .co, .io, .org, or net. While most service these days will automatically create SPF and DKIM records for you, it's important to check if this is correctly set up for your domain. Messages without proper SPF and DKIM records stand a very high chance of being blocked, marked as Spam, or arriving with warning labels attached to them. ## What are SPF, DKIM, and DMARC? **SPF (Sender Policy Framework)**: An email authentication technique that allows domain owners to specify which mail servers are authorized to send emails on their behalf, helping to prevent email spoofing and improve deliverability. **DKIM (DomainKeys Identified Mail)**: An authentication method that allows senders to attach a digital signature to emails, verifying the message's origin and ensuring it hasn't been altered during delivery. **DMARC (Domain-based Message Authentication, Reporting & Conformance)**: An email authentication protocol that helps domain owners prevent email spoofing by specifying how to handle messages that fail SPF or DKIM checks. It also provides reports on email authentication activity. > Improve email deliverability from Close. Avoid spam filters, follow sending best practices, and set up SPF, DKIM, and DMARC for your domain. ## Docs - [Connecting Microsoft 365 in managed tenants (Entra admin guide)](https://help.close.com/technical-support/email-deliverability/connecting-microsoft-365-in-managed-tenants-entra-admin-guide.md): How Microsoft Entra administrators grant admin consent for the Close app: the full list of permissions Close requests, why calendar permissions are required, and how to fix the "Administrator approval required" screen. - [Email Sending Limits](https://help.close.com/technical-support/email-deliverability/email-sending-limits.md): Set email sending limits in Close to stay under your provider's daily thresholds. How limits, sending priority, bulk email, and Workflows interact. - [Requirements for bulk email senders](https://help.close.com/technical-support/email-deliverability/requirements-for-bulk-email-senders.md): Google and Yahoo bulk sender requirements for email from Close: SPF, DKIM, DMARC, PTR records, TLS, one-click unsubscribe, and spam rate limits. - [Which IP addresses need access to my SMTP/IMAP server?](https://help.close.com/technical-support/email-deliverability/which-ip-addresses-need-access-to-my-smtpimap-server.md): The IP addresses to allowlist on your SMTP and IMAP servers so Close can send and sync email in restricted corporate or IT environments. - [Office365 connected accounts](https://help.close.com/technical-support/email-deliverability/office365-connected-accounts.md): Fix Office 365 accounts that disconnect from Close or won't send or sync email. Enable SMTP AUTH and IMAP, and resolve Windows SSO issues.