More people are using new technology to notify their partners that they’ve been exposed to a sexually transmitted infection (STI)—they’re sending the alerts via electronic postcards, or e-cards, Reuters reports.

Partner notification, which has long been a way of controlling the spread of STIs such as HIV, is traditionally done over the phone, in person or with the help of a public health worker. In 2004, a San Francisco-area nonprofit called Internet Sexuality Information Services (ISIS) produced inSPOT, an Internet-based program to aid in partner notification.

According to the article, website users choose one of six e-cards, type in recipients’ e-mail addresses and either send the postcard anonymously or include their own e-mail addresses. The e-card warns recipients that they might have been exposed to an STI and provides them with links to STI information and a map of clinics where they can be tested.

Since 2004, more than 30,000 people have sent nearly 50,000 e-cards to their sexual partners. “E-cards do not replace in-person communication,” says Deb Levine, the executive director of ISIS. “But for people who are diagnosed with an [STI], e-cards can enhance sexual communication and help with community responsibility and easing a process of disclosure that can be extremely difficult.”