Develop a flat, minimalistic icon that encapsulates 'Customer Follow-Up.' The icon should include a symbolic representation of ongoing support and communication, such as a telephone, an email symbol, or a speech bubble, to convey the idea of continued engagement with clients. The chosen symbol should be outlined in black for clarity and simplicity. Add an orange check mark or an orange looped arrow around or beside the communication symbol to signify the ongoing nature of the follow-up process and the commitment to customer satisfaction. Ensure the icon is designed with clean lines and minimal detailing to maintain the visual coherence of your website's theme. The icon should be easily scalable, instantly recognizable, and seamlessly integrate with the other service icons on your 'Immobilien Hauf' website, effectively communicating the importance you place on maintaining relationships with your clients post-transaction.