You can accept Kaspersky’s SSL certificate as valid by adding the certificate to the list of exceptions in Postbox. This will cause Postbox to complain about invalid certificates. Kaspersky will intercept your mail connections, inject itself between Postbox and your mail server, and use its own certificates to protect the 'last mile' of your connectivity. Kaspersky will scan encrypted connections, including IMAP/SMTP over SSL between Postbox and your mail servers. Since SSL provides a secure connection, this feature offers extra protection for connections that should already be secure. The issue is with an anti-virus setting that scans connections that use the SSL security protocol. If you use anti-virus software, you may see an error message about an invalid security certificate when you're setting up an account or when you're fetching mail from an account.
