How To Write A Harsh Reminder Letter . Hi simon, just a reminder from jessica james massage therapist about your appointment on 20 th may at 4.15pm. Till now, i didn't receive your mail. LETTER OF RESIGNATION FROM TEACHING POSITION Sample & Templates from www.sampleletter1.com Unless this is a reminder letter for friendly purposes, stick to the standard formal tone. The greeting or salutation you choose will depend on how familiar you are with the recipient. If you don’t know where to start with writing a friendly reminder email, consider the following three tips.