Notifications of IncaMail messages are always provided with a signature for security reasons. Please always check the validity of the signature and the sender. The sender of the e-mail should always be as follows: swisspost@im.post.ch
Unfortunately, some e-mail clients and web mailers show the signature to be invalid or unknown, despite the fact that the certificate is valid. This is normal after the certificate has expired, even if it was still valid when it was sent. In these cases, a manual inspection of the relevant certificate is recommended.