Well, for one the hassles of writing an invoice for 25 cent is lot more expensive than just giving them away. In the same vein, if you work in a big company and need to go through purchase to get an order for 25 cent is often impossible. So the cheapest way to handle those samples are to give them away. That hobbyist can take advantage of this is probably unfortunate but not a major concern. Seems that they try to curb the worst excesses by not allowing request from generic mail domains and people ordering too many samples.
Yeah. My local engineering company has given me a few things for free when I have only wanted, say 4 bolts or so. Saves them noting it all down and printing out a massive full page invoice.
HOW ? well i tried many things online but they don't seem to have generic Emails
Well I have a few of my own domain names so I use email addresses from them. Obviously if you don't then it's a bit more tricky.
You can buy yourself a domain name and get email on it for about £20 a year (or less). Then you also have the option of making a website on that domain name in the future if you want your own website.
On another note, I'm not sure if the random domain addresses you can get at mail.com would be classed as generic domains by maxim.