Guide

1. Inside SendGrid's Design Editor, head over to the left-side panel and tap the 'Tags' tab.

2. Find the merge tag you want to use, then click the 'Copy' button next to it. Since you're personalizing emails, consider choosing "first_name", "last_name", "email", and other similar options that represent the personal details of the recipients.

3. After that, go to the preview area and select the text module you wish to edit.

4. Paste the selected merge tag into the content. In this case, you can place the first name substitution next to the email greeting.

5. Following that, click anywhere outside the selected module and then repeat the same series of steps until all custom values you want to use are added to your email.

6. Finally, click 'Save' to apply the changes.