Explanation
A custom redirect is a special URL that tracks link clicks and conversions for any online marketing content. If a prospect clicks on a custom redirect after filling out a form, the prospect's assigned Marketing Cloud Account Engagement campaign will change only if the Marketing Cloud Account Engagement completion action for the custom redirect is set to change the campaign. Otherwise, the prospect's campaign will remain the same, since it is based on the first touchpoint. The page that the custom redirect links to does not affect the prospect's campaign. References: Custom Redirects, Completion Actions, [Marketing Cloud Account Engagement Campaigns]

When working on a list email, the Marketing Manager has three options that are not available when working on an Account Engagement email template. They are:
Ability to send the email immediately. This option allows the Marketing Manager to send the list email to the selected recipients as soon as the email is ready, without scheduling it for a later date or time. This option is useful for urgent or time-sensitive messages6 Ability to schedule the email. This option allows the Marketing Manager to choose a specific date and time to send the list email to the selected recipients. This option is useful for planning ahead or aligning with the best time to reach the audience6 Recipient and suppression lists. This option allows the Marketing Manager to select which lists of prospects will receive the list email, and which lists of prospects will be excluded from receiving the list email. This option is useful for targeting and segmenting the audience based on their attributes or behaviors6

In Salesforce Pardot, enhancing form security and preventing bot submissions can be effectively managed using two specific settings: reCaptcha and the Honeypot Technique.
reCaptcha: This is a service provided by Google that helps protect websites from spam and abuse. A "CAPTCHA" is a turing test to tell human and bots apart. It is easy for humans to solve, but hard for "bots" and other malicious software to figure out. By integrating reCaptcha, forms can verify that the person submitting the form is indeed a human, thus adding a layer of security against automated attacks.
Honeypot Technique: This is a clever and non-intrusive method of detecting bots. It involves adding an additional field to the form that is invisible to human users but visible to bots. The principle here is that while a human won't see or interact with this hidden field, a bot will typically attempt to fill it out. When the form is submitted, if data is found in the honeypot field, the submission can be flagged as coming from a bot and thus be ignored or handled differently.
Both options are specifically tailored to enhance the security of forms in Pardot, helping to mitigate unwanted bot traffic and ensuring that engagement and leads generated are genuine.

Explanation
The combination of automation tools that LenoxSoft should use to achieve their goal is an automation rule and a completion action. An automation rule is a rule that runs continuously in the background and matches prospects based on the criteria you set. A completion action is an action that Marketing Cloud Account Engagement executes after a prospect successfully completes a desired activity, such as submitting a form or clicking a custom link1. LenoxSoft can use an automation rule to update the custom field for anyone who has submitted the form before today, and a completion action to update the custom field for anyone who submits the form moving forward.

An automation rule can match a prospect more than once if you enable Repeat Rule. Otherwise, an automation rule will only affect a prospect one time.
Explanation:
An automation rule is a criteria-based action that is triggered when a prospect matches the rule. By default, an automation rule will only affect a prospect one time, unless you enable the Repeat Rule option. If you enable the Repeat Rule option, the automation rule can match a prospect more than once, as long as they meet the criteria each time. Automation rules do not run every time, since they are evaluated based on a schedule that you can set. Reference: [Automation Rules], [Repeat Automation Rules]