REDCap - Designate an email field for communication
By enabling this feature, REDCap can direct specific email communications to the email address provided. This includes sending survey invitations, automated survey invitations, survey confirmation emails, and Alerts & Notifications. If a field is designated for that purpose, then any records in your project that have an email address captured for that particular field will have that email address show up as the participant's email address in the Participant List (unless an email address has already been entered for that participant in the Participant List directly).
Using the designated email address field can be especially valuable when your first data collection instrument is not enabled as a survey while one or more other instruments have been enabled as surveys. Since email addresses can only be entered into the Participant List directly for the first data collection instrument, the designated email field provides another opportunity to capture the email address of survey participants.
Please be aware that designating an email field means that survey responses can NEVER BE ANONYMOUS because of the fact that the participant's email address can be viewed on a data entry form, which means it is easy to identify the record/response to which the email address belongs.
NOTE: If the participant's email address has already been captured directly in the Participant List, then that email address will supersede the value of the email field here when survey invitations are sent to the participant. Also, if the email invitation field exists on multiple longitudinal events, on a repeating instrument, or on a repeating event, the field's value will be synchronized across all instances/events so that changing it in one location will change the value across all events/instances where the field appears.
Survey-specific email invitation field: While the email invitation field discussed here is a project-level setting, it is helpful to know that there also exists a survey-level email invitation field option that can be utilized for particular surveys in the project (whereas the project-level field would be applied to ALL surveys). A survey-specific email invitation field can be enabled for any given survey, in which you can designate any email field in your project to use for sending survey invitations for that particular survey. Thus, you can collect several email addresses (e.g., for a student, a parent, and a teacher) and utilize each email for a different survey in the project. Then you can send each person an invitation to their own survey, after which all the survey responses get stored as one single record in the project. See the 'Survey Settings' page in the Online Designer for this survey-level setting.