If you notice a red 'Opt out of email' button on a contact card, it signifies that the contact is no longer receiving email communication. There are several reasons this might happen:Your contact has chosen to opt out of receiving emails.Your contact's email provider has opted them out.If your contact has chosen to opt out of receiving emails then we recommend that you confirm with the end user their willingness to receive emails again. You can reach out to the end user via an alternative communication method, such as a phone call or text message, to obtain their consent.To opt them back in for email communication, you can click the red 'Opted out of email' button.If your contact's email provider has opted them out or encountered any issues while opting users back into emails, please contact our support team at support@getoiling.com. We may need to investigate further to resolve the issue and ensure that your users' email preferences are correctly updated.