As China's leading email products and solutions provider, Coremail, the company focuses on email technology and services, concentrating on one-stop solutions to all email security issues, with products covering email security gateway, email data leakage prevention EDLP, CAC2.0 anti-phishing anti-theft, anti-phishing drills, and so on.

In 2014 Coremail released the world's first Chinese domain name email registration platform. Based on years of working experience, Coremail believes that Han script single character Internationalized Domain Names (IDNs) may bring more difficulties and challenges to anti-phishing and anti-spam work, which is reflected in the following aspects.

First, the existing anti-spam system mainly relies on the analysis of domain names and IP addresses. The introduction of Han script single character IDNs will make it difficult for these systems to identify and process spam features, thus reducing the effectiveness of anti-spam.

Secondly, Han script single character IDNs can be used to send phishing and fraudulent emails because URLs constructed on the basis of Han script single character TLDs are more difficult to recognise and easier for users to trust. Attackers may take advantage of this to deceive users and increase the success rate of phishing and scam emails.

Third, existing anti-spam strategies may need to be updated and adapted to meet the new challenges posed by Han script single character IDNs. This includes updating blacklists, whitelists and greylists, as well as improving spam identification algorithms.

Fourthly, Han script single character IDNs are not easily recognisable in textual contexts, posing difficulties for anti-phishing, spam/SMS filtering, and so on.

So we believe that the risks associated with opening up Han script single character IDNs far outweigh the possible benefits.