Explanation
Drip programs are automated email campaigns that send a series of messages to prospects based on predefined criteria and triggers. You can pause and resume drip programs at any time. However, when you resume a drip program, it does not start immediately. It takes up to one hour for the drip program to resume sending emails to the prospects in the program. It does not take 5 minutes, one business day, or immediately for the drip program to start after unpausing it. References: Drip Programs, Pause and Resume Drip Programs

The GoToWebinar connector is a feature that allows you to integrate Marketing Cloud Account Engagement with GoToWebinar, a web conferencing platform. With this connector, you can:
* Register prospects for GoToWebinar events from Marketing Cloud Account Engagement forms, landing pages, or completion actions.
* Automatically pull in prospects who exist in GoToWebinar but not Marketing Cloud Account Engagement and create new prospect records for them.
* Display registrations and attendance as activities on the prospect's record and use them as criteria for segmentation, automation, and reporting. References: [GoToWebinar Connector], [Set Up the GoToWebinar Connector]

To see why the email was not sent to the prospect, the marketing manager should refer to the list email send report to see if a suppression list was used. A suppression list is a list of prospects who should not receive a specific email, even if they are on the recipient list. If the prospect was on a suppression list, they would not receive the email. The other options are not likely to explain why the email was not sent, as the prospect was already on the recipient list and was mailable

Explanation
According to the Salesforce documentation, an automation rule is an automation tool that can be used to send an email to a prospect when a form is submitted and a specific field value is selected on that form. An automation rule can be configured to trigger an action (such as sending an email) when a prospect meets certain criteria (such as submitting a form and having a specific field value). The criteria can be set to Match All or Match Any, depending on the logic required. In this case, the Match All option should be used, as the prospect needs to meet both conditions (form submission and field value) to receive the email. A completion action is another automation tool that can be used to perform an action after a prospect successfully completes a form, but it cannot be used to check for a specific field value. A dynamic list is a list of prospects that is updated automatically based on certain criteria, but it cannot be used to send an email directly. A list email is an email that is sent to a specific list of prospects, but it cannot be triggered by a form submission or a field value. References: Salesforce documentation

Explanation
Mailable prospects are prospects who have opted in to receive email communication from you and have not bounced or unsubscribed. You can find the number of mailable prospects in your database by navigating to the prospect list and selecting "Mailable Prospects" from the dropdown menu. You can also filter the list by tags, campaigns, or custom fields to segment your mailable prospects. References: [Mailable Prospects], [Filter Prospects]