Are emails from employees in large companies nowadays monitored and controlled by default?

An acquaintance of mine once sent some company data to his private email address because he wanted to work on his own laptop with it (so no bad intentions). A week later, he was terminated because the company (large company with almost 1000 employees) has discovered that in his mails. I wonder how big companies do that. Do some specialists in an IT department sit somewhere and read every mail? They would have to read about 20,000 mails a day. That monitoring and access to mails is now almost everywhere allowed is always read but how it is done in such a large company, I do not quite understand.

They will not read all emails. There are keywords that the emails are controlled. As an extreme example: You send an e-mail with the content "secret documents", then they will definitely be monitored. And company emails can also be monitored in mMn.

There does not have to be a person sitting there reading the mails. This is done by a program.

About the same as your spam folder.

If the program notices that something is wrong, the email will be reported and only then someone will look at it.

But how does a program notice something like that? One sends in the office everyday also many mails with attachments.

And how do such filters work?

You must not ask me that. I know that algorithms recognize certain keywords and / or connections, and of course they can distinguish the mail addresses that belong to the group of companies or are private. More or more details are unknown to me. But I honestly synonymous completely Schnuppe.

Thanks anyway for the answer. I find that interesting because in my company private mails are not prohibited and I've already written one or the other times private mails and the idea unpleasant that someone can read along.

Well, no one is sitting in a quiet little room reading the mails day by day. Then he or she would have a lot to do.