Issue free SSL certificates by adding a DNS TXT record. Keys are generated in this browser and never sent anywhere. Download your files before closing the tab.
1Domains and options
2Add these TXT records at your DNS host
Many DNS panels want only the host part (for example _acme-challenge.mail) and add the zone themselves. Use a low TTL such as 60–300 seconds. If two rows share a name, add both values as separate TXT records.
| Domain | Type | Name | Value | Public DNS |
|---|
3Your certificate
Exchange 2013 / Exchange Management Shell
Copy the .pfx to the server first. Enabling for SMTP will ask to overwrite the default SMTP certificate; answer Yes only if you want this certificate used for mail transport.
IIS
Double-click the .pfx, choose Local Machine, enter the password, and place it in the Personal store. Then in IIS Manager open the site, choose Bindings, edit the https binding and select the new certificate.
Nginx / Apache
Let's Encrypt certificates are short-lived. Run this tool again before the expiry date shown above. If you renew soon after, Let's Encrypt may reuse the earlier DNS validation and skip step 2.