Email has revolutionised the way people communicate. I would guess the vast majority of correspondence, both meaningful and junk, is now sent by electronically. That includes scams.
Most people of a certain age can remember those flyers coming through the door declaring that you'd won £1,000,000! All you had to do was ring a premium rate number for 15 minutes whilst a recorded voice explained various things and then you heard nothing further. Of course most of the people who were fooled into thinking they had won a competition they had never entered were children or the mentally impaired but the number of them that came through the door suggests there must have been quite a few who did.
The email equivalent are either phishing emails, probate or property scams. Small scale scams can involve an ad on a local website, like Gumtree, advertising a fantastic flat to rent really cheaply; the only problem is that the owner lives abroad and can't show you around just now - however if you send them a month's rent they post or have someone drop off the keys. More sophisticated ones involve fairly elaborate emails and mock ups of trusted corporate websites - like your bank's - requesting your login details.
The probate scam is a rough combination of the two. They use a trusted person or organisation's details, such as a solicitor, to email people to tell them that someone with their surname has died and that they could inherit lots of money; the only trouble is, the inheritance tax has to be paid before they can obtain probate (which is true). A friend of mine experienced this personally. Someone emailed a lot of people in Australia and New Zealand to say that someone with their surname had died and that there may or may not be some relation - regardless, this person was prepared to get probate for them.
This friend had a lot of people contact him, most to say his name was being used in a scam, some to double-check they weren't missing out and a very few in the hope it was true. Being commonwealth countries, the would-be victims enjoyed the knowledge that (a) an Oxford educated solicitor is unlikely to make many spelling mistakes and (b) would not be referring to themselves as 'attorney' or 'chief counsel to the late...' In fact, this has been one of the easiest ways to tell a scam email in the past - the use of American English: 'license' instead of 'licence'; 'practicing instead of 'practising'; 'attorney' instead of 'solicitor'. Now that the majority of the world's population are learning American English, it's getting harder to tell the difference - even a packet of Fairy washing powder I bought told me to separate my 'colors' from my 'whites'. But the most basic point remains valid: if it sounds too good to be true, it probably is.