How are files sent by email?

Question

Email

We plan to raise the mail server. Searching for information turned up a lot of data (more on that in the next question), but it is clear that different mail servers and clients transmit mail via SMTP. But smtp does not support file transfer (this is a text protocol), and mail reading protocols also do not work well with files (I don’t know POP3, but IMAP seems to be with crutches). And how then can I send a file from mail to Outlook and receive it on Yandex.Mail or how can I send a file from Gmail and receive it on Outlook. How is file transfer implemented in mail services?!

Answer 1

Start with this article
https://ru.wikipedia.org/wiki/MIME
If it's very rough, then binary files are encoded into text strings, and the program will decode them back.
However, mailers also have their own extensions, including those that solve this problem.
In general, the topic is extensive, but hardly interesting for the application, just run diagonally to get an idea

Answer 2

But smtp does not support file transfer

How does it support :) Do you think that "beautiful" letters that are "typed" by especially gifted people - are they transmitted in some mystical way?

MAP like with crutches

Wrong. There are no crutches there. Millions of people around the world receive and transfer files via smtp/imap

Answer 3

Non-text data is encoded in base64 format , as indicated in the message header or part of a multipart message.
Content-Transfer-Encoding: base64