Certificate-Not-Valid-IMAP/EN/Background

Server certificates provide more security on the Internet and serve to verify (authenticity) the identity of servers. A certificate is issued by official, trustworthy institutions. A certificate is not forgeable. In normal life, a certificate is comparable to an identity card or a notarial certification. Similar to a passport, certificates also have a certain validity period. Certificates thus ensure secure data exchange and form an important basis of trust for operators, e.g. of online shops.