Future Reminders can be sent as Emails, SMS, Letters, or internal Tasks that can be created. You can customize the content of the Reminders using placeholders to pull CRM information into your reminders.
In the Web Portal go to Jobs > Job Type Templates > (Either Create a New Job Type or Edit an Existing Job Type) > select the Future Reminders tab.
You can also have more than one reminder type set up for a job, by pressing the + button to add multiple future reminders. For example, if you would like an email to be sent a week before the job, and then an SMS a day before, and a task reminder for your users that the job is due to be done. You can also set reminders to be sent after a job has been completed, by setting up a Job Status Update (How do I add a Job Status Update?)
Once you have selected the reminder type, then you can begin filling out other details for the reminder, such as where it will be sending, whether there is a reminder type template that you have created and would like to use, and the body of the message. Placeholders can be used in most of these fields by pressing Ctrl + Space and selecting the placeholder from the dropdown that appears.
Any placeholders that are red when selected, will not fill out the value that it is related to.
Once you've finished creating the reminder(s), then click on the Save button at the bottom.