I have 100 files. Each of them is 2 MB. I would like to send via email everything at once as attachments (no hosting on Gdrive or somewhere else). Is there any way to do it? Ideally I'd prefer to use Gmail web interface, but other apps would be OK as well.
Nope, the attachment limit is pretty hard on gmail.
Even clients of paid options of gmail can't go beyond these limits.
The hosted option is the way to go.
You must remember that there are two limits regarding maximum size. What the sending system will allow and what the receiving system will allow. Even if you could send an email that is extra large, the recipients system might reject it.
You might be able to gain some space by compressing the files first. Use your favorite Zip application to reduce the file size. How much space can be saved will depend on the contents of the original files. Some save zero and some save 50%. Some of these applications will even take a folder and output a series of files that are the correct size. With luck you can reduce the number of emails.