The main thing gmail offered back then was a frickin GB of email storage. (Which spawned a host of other things, like a FUSE filesystem backed by Gmail.) No other free provider was even close! Hotmail offered email measured in 10s of MB and I'm sure Yahoo was similar.

(I got my first gmail account in 2004.)

Yeah, the UI wasn't bad, but there was less email back then and I didn't (still don't) really mind being served HTML repeatedly instead of some "AJAX" application, which is what I remember the technique being called. (It used to be the latency to the server was poor and JS hid that; now, on 2-3ms fiber, it seems that the JS actually introduces a lot more latency than it hides.)

Hotmail provided just 2MB of space when gmail launched on 01 Apr 2004. They increased it to 250MB in June 2004.

source: https://www.pcworld.com/article/116657/article.html

I used Yahoo Mail at the time, which had a limit of 6MB (and IIRC that had been an increase at some point). Soon after GMail came out they upped that to 250MB. Searching now I find an article saying this happened December 2004. I seem to remember it happening closer to the GMail announcement though but I could be wrong.

Does FastMail let you have complex conditions in filters though? One huge value of Gmail for me is that I can have arbitrarily complex nested conditions to filter mail using a formula. I've been looking for even more flexible filtering (e.g. custom scripts) and yet I have not even come across anything on par with it.

fastmail lets you write complete scripts for filtering using the Sieve programming language. https://www.fastmail.com/help/technical/sieve.html

Sieve is great. I highly recommend it over, say, procmail, or Outlook filters (especially Outlook Web Access).

Isn't procmail dead?

What does dead mean to you? It still compiles and you can install it from various binary repositories.

It's not even maintained and the official site seems long gone. How do you see this as alive?

Holy cow, I will have to look into this. Thanks a ton!!

filters cannot be applied retroactively, however.

be sure to write your filters before receiving anything. Especially important if you're importing your email for the first time... and insanely annoying if you want to debug such an advanced filter.

as always with fastmail: It has great features... but always with a massive caveat.

Ooooof, wow, thanks for the heads up. There's no way that's going to work... I edit my filters and apply them retroactively... There's no way I can set them in stone the first time. :( is there any email service that doesn't have this limitation?

Its not on FastMail, its on Sieve. It is a hook that runs on receiving. To my knowledge if you want Sieve this is the only option. I use it with Protonmail and it is the same way. I also run it on my own mailserver.

One nice thing, for me at least, is it runs prior to the email ending up in your inbox and I am uses to Outlook rules were rules execute post arrival.

Sieve is an RFC email language. There's no reason Sieve recipes couldn't be applied to a corpus of existing email; that's an implementation detail of FastMail. Sure, it isn't necessarily the same as pre-receive (for example, anything you discarded the first time isn't going to show up again, and any manipulations made the first time aren't going to undo themselves). But it could be done; it's not really Sieve's problem.

Wouldn't using something like https://github.com/lefcha/imapfilter also be an option?

It would be awesome if some day there was a "jmapfilter". I think JMAP would be really efficient for this use case.

Most of my filters are simple searches. And if you can search, you can apply it retroactively.

Also FastMail’s search works for any email header so it can be more potent than that of Gmail.

I wonder why can’t they add a checkbox to apply the rules retroactively. Seems to be simple enough.