HouseCall Pro does not allow the sending of mass emails to large customer lists. You can set up email campaigns through HouseCall Pro that allow you to send emails to customers before or after jobs are completed.
Email campaigns are meant to allow you to follow up with customers. You can set up a Thank You email that is sent a few days after a job is completed or a reminder email that goes out months after a job is completed encouraging repeat service.
We recommend using MailChimp if you'd to send mass emails to your customers. You can export your customer list from HouseCall Pro and then import it into MailChimp