That's an interesting observation. An e-mail client that would allow you to route e-mails to different folders on your system (not folders within its own filesystem or database) would be very powerful, especially for developers. Do you know of such a program?

It was quite standard in the “old days” — I just read my mail in Emacs from around ‘78 to around ‘98 and filed my mail in directories all over my system. Mutt, elm, mm etc all worked this way iirc. I blame the arrival of the PC for the silo approach to apps in general.

As for simply delivering them to other directories: that’s pretty easy depending on what very agent you use (Postfix, qmail, sendmail etc). They are all designed to support that. It’s the clients that struggle.

On a similar vein, how easy is it to programmatically process emails? I receive a report every day as an email attachment that I would like to process automatically. Right now, I’m doing part where I open the email and download it manually.

You could retrieve it from your mail server via IMAP (say with tiny program like fetchmail) and pope them through whatever program you like.

I run my own server so info stuff like this automatically as the mail comes in.

The people saying “use smtp” don’t know what they are talking about: SMTP is the protocol for delivering mail to a host. You want to process the message as or after it arrives.

I was able to process my Gmail with a simple python script that accessed email via SMTP (using smtplib, I think it was) a long time ago, it can't be too hard.

At the time I was only experimenting with it for an idea I never fully realized, creating a system for video games to automatically play games asynchronously using email instead of a server (also you could see it was your turn again just by email notifications), thus being able to survive in perpetuity as long as SMTP remained a thing, but I could see using it to do what you're suggesting as well.

The doesn't sound very difficult if you can get the email via SMTP. I'm sure there's dozens of APIs that can do it, and in the realm I'm most familiar with, I think you could use Rails' Action Mailbox to take incoming email and process it. It's overengineered for a simple task, of course.

You could use Mailgun for this: https://www.mailgun.com/email-parsing-software