The following is a guest post from SendGrid’s Compliance Desk. Registration forms are a great way to follow up people’s interest in what you are offering on your website. Unfortunately, registration forms can be a large source of a sender acquiring bounced addresses and spam traps, which could cause your business to spam a host’s mailbox without proper validation of addresses. This can result in a lower SendGrid internal reputation score, as well as reflect poorly upon your business. Fortunately, there are many helpful techniques that can help a sender avoid many of the issue that can come up through their registration form. Require a Double Entry Email Address Sometimes in the registration process users make mistakes entering their email addresses, such as firstname.lastname@example.org or person@@domain.com. By entering the email address twice and having a system in place that checks that the addresses match up, the person entering their email address has a much smaller chance of accidentally entering an invalid address. This practice is debated in user experience circles because a common user reaction is to copy and paste the email address. Captcha-block the Bots A good technique in protecting your registration form from automated bots is placing a required Captcha in the form. A Captcha is a test to ensure that form is filled out by a human being as opposed to a bot. The image is not replicable by a bot but easily replicated by a human being. Send a Confirmation Email One common issue that arises with email registration forms is people using false or fake addresses. To prevent this, you can require a Double Opt-In Email, confirming that their address exists. A double opt-in email not only helps ensure that there is an actual human being registering but also validates that the recipient did indeed sign up for your registration. There are many great techniques available to protect your registration form but a balance must be created between user friendliness and security. Some forms have many required fields in registering as well as checks to make sure that the form is filled out correctly. Too many fields can drive away potential interest in your site or product. One way to balance out the registration process is to have other information about the person be collected on a landing page after the registration form is done. This serves to be both user friendly, as well as allow you to collect valuable information. No matter what method you choose to ensure the quality of collected email addresses, the result is that you should only be sending to valid addresses with recipients who expect to receive an email from you.