If we start with 'If you would like to become a member of ELM, please fill out the enclosed membership form and send it back at your earliest convenience.', does it make sense to conclude with 'To join the ELM, just fill out the attached membership form.'
If you would like to become a member of ELM, please fill out the enclosed membership form and send it back at your earliest convenience.###To join the ELM, just fill out the attached membership form.