You have to stick around after you send the job, just in case. Make sure they know you won't be around after a particular hour and ask them to confirm that the file you sent was received and can be processed. As well, the professional is creative and gets things done. If no one is there, you fax them the document. If the fax machine does not pick up, you call their answering machine.
Professionals solve problems.
This also means that you should try to help your clients with problems. I have helped numerous clients troubleshoot a computer network, BBS, or software incompatibility over the phone while negotiating or discussing a job. Translators must stand by their work. Regardless of how offended or angered you are by such claims, take the time to work through the problem with the client. Ask for specific comments, such as where the errors are, what kind they are, and how many there are.