First of all, I would like to immediately note the security of email services on various web servers: the most unprotected in increasing order, starting with the most "leaky" one: rambler.ru; mail.ru; yandex.ru; gmail.com (these are the most popular, others have not been tested). I only want to note positively gmail.com - “hacking” is very difficult, plus it does not apply to the zone of the “.ru” national domain, which means it’s practically impossible to delve into your mailbox (for the rest, you only need a court order, well, in what cases it can be said I won’t get it, everyone has operational experience, you yourself know). Plus, on all these mail web servers, there are administrators (including duty administrators), and these are people who are more likely to "break through" than electronic protection. Hence the conclusion: if you want a secure mailbox that is not controlled by "third" parties, start your own mail server. Most have their own sites, which means (as far as I know, this is included in the services provided and in payment for using a domain name) 5 free mailboxes of the format
ivan@gradus.ru (where ivan is the unique username and gradus.ru is the domain name of your site). In this case, the responsibility for mail security lies with the site administrator and his professionalism. If you need more mailboxes, you must already install a mail server (from personal experience I can recommend for Windows: MDaemon and Kerio are easy to use and reliable, with qualified administration they are practically “impenetrable”, I don’t know for Linux). Of course, there were cases of hacking and mail servers (as well as sites), but this is already more a question for the professionalism of admins.
I would also like to note methods of protection against programs like Brutus. Though stupid, they can shoot a stick once a year. The main principle of the work of such programs is the enumeration of words, characters from the existing dictionary, for this reason they are very limited in their capabilities - how many options you have scored in the dictionary, how many options the program will try. In this regard, they are very easy to deceive: use numbers and letters as a password; entering a passphrase in another layout (if the word is Russian, then in the English layout and vice versa); adding a punctuation mark at the end or beginning of a passphrase ... You can still give a bunch of methods, but these are the simplest and most reliable. I would also like to note that a combination of the above methods significantly enhances protection, but it still does not save rambler, mail, yandex, gmail from security holes. I won’t talk about holes (I don’t work for them and they don’t pay me for this), and believe me enough. Either they don’t have a specialist in this field at all, either he is an amateur or the Russian mentality (well, they’ve stolen the box, well, the cant is safe, who should you show it to?) ... Using mail.ru as an example, I experimentally tried to understand the problem of box theft, “polite message nah ”- there is no other way to call the reaction. “Why spend money on the security of free mailboxes? Hijacked? Get another one ... ”- this is what these services should have. So think and decide for yourself ...