From your ZenMaid dashboard, go to Contacts > All Contacts.

Then, search for your lead using the search bar. Select the lead by clicking on his/her name on the search result.

On the next page, ensure that the lead has an email address record on file. If not, you wouldn't be able to send an estimate to this lead unless you add one.

Once you confirm that the lead has an email address on your record, click on the Actions button then pick Send Email.

On the pop-up window, select Estimate for the template field then hit the Generate Email button.

Another pop-up window will appear that will let you edit the email's subject, body (content as well as formatting), recipients (if you'd like to send a copy to yourself/office as well).

Once done polishing, just click the Send Email button at the bottom of the pop-up window.

If you wish to edit your Estimate email template, just go to Settings > Emails and Texts and on the next page, click on the Estimate tab right under the Email Templates section.