Could you provide a short English letter to introduce people to Islam and invite them to it?

Thank you for your eagerness to invite people to the religion of Allah. Be assured of immense reward, for the Prophet, peace and blessings be upon him, said: "For Allah to guide a single man through you is better for you than possessing red camels." Da'wah has become easier in this era through the internet, as you can send reliable da'wah links to your acquaintances via email.