[jacquesm]

My 1K+ folders and millions of archived emails disagree with you. I've yet to find a client that works as well as Thunderbird with my massive email archive.

Why would it be slow? I can only type so fast and sending/receiving mail is mostly dependent on the connectivity, not on the software.

[webwanderings]

I recently downloaded TB to move some offline mbox emails of large quantity. TB became increasingly slow processing few thousand. I downloaded Opera Mail to do the same exact work. I was done within few hours.

I have a need for more people to repeat the same process. There's zero chance I'll be asking them to download TB.

[cat199]

TB by default saves 1x file per folder (e.g. MBox like) -

This means depending on your storage configuration and how you use folders, potentially writing 100MB, 1G, 10G, etc. back to disk on folder content change.

For batch processing though, I use the CLI tools - thunderbird is view/compose only (procmail/formail/archivemail/offlineimap,etc)

I was hitting performance probs on bigger folders, and setup some more strict archiving to archive older mails to subfolders/zap offline using an 'archivemail' job, etc, and the problem went away, with TB being quite snappy.

as I understand it there was some effort to support 1-file-per-email, which might be an option now, but this has it's problems too.

Outlook has it's PST corruption hell...

Basically, in my opinion, email is a pain, each client shows it differently, though I am admittedly not up to speed on Opera Mail.

[jacquesm]

Thunderbird sets up a full-text index to allow you to search your emails. This eats up a bit of time while importing large mailboxes but is quite handy once it is done.

[webwanderings]

I tried that (I googled to see what am I missing) didn't help.

[lmm]

How does KMail perform for that? I never had trouble with its performance, though I don't think I ever quite made it into the millions of emails.

[lizzard]

Thunderbird searches can be quite slow.

[BinaryIdiot]

> My 1K+ folders and millions of archived emails disagree with you.

You seem to be attempting to address just the slowness of my complain and not its overall awfulness. Start-up time, loading each email; I've never seen it work very fast it always has that android-like lag throughout the entire thing. It also doesn't feel native to whatever OS you're using it in almost like using a Swing app.

The UX is just awful.

[jacquesm]

Well, maybe I'm just used to it. I tried many other email clients and other than text mode ones it is the best I've found so far (Linux, Debian).