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Outlook 2011 but that's because I have an Exchange account.

What mail app do you use on your mac?
"Why?" is really more important than just "What?". Why allows you to determine if the criteria of the person replying matter to you or not.

Gmail with Google Chrome...I've never seen a good reason to use a dedicated email client, but that's just me.
Just you. Well not just you
It's never just one person. No mass released solution only has one person using it. What calb meant was "that's subjective".
 
The provided mail.app. It handles multiple email accounts across different providers; it connects to the local address book which syncs automatically with my iOS devices; the rules based engine so far has met my needs and it handles large mail folders.

My wife also uses the default mail.app and she gets LOTS of mail daily. So far I've not heard of any serious issues she has aside from keeping her mailbox down to a reasonable size. She got sick and in the course of her recovery received nearly 2,000 emails.

As someone has already said, look to the "why" a person uses a particular program, not the "what" because the one should have some criteria to base a decision on.
 
Thunderbird.

It is everywhere I need to be. Mac OS X, Solaris, FreeBSD.

Plus all the plugins. No one else comes close to touching all the plugins.
 
Mail is an amateur app and does not work for integrated business use. I have to admit I have not looked at Thunderbird for some years, as it was good back in 2003 but had not moved on.

Couldn't agree more with your comments on Mail. Some of it is really well designed and the rest not worth bothering with.

On another related note? Does Thunderbird or one it's plugins now offer more advanced mail filtering rules?

For example can one combine and and or in the same rule, similar to what Outlokk Ezpress could do way back in 2000? That is what stopped me switching to it in 2009.
 
Gmail with Google Chrome...I've never seen a good reason to use a dedicated email client, but that's just me.

I just use gmail with Google Chrome as well... It suits me perfectly fine... On my iphone I use the built in mail app tho.
 
I use Mail. Exotic, I know. :/

I've used Sparrow and I like it as well.
 
Thunderbird.

It is everywhere I need to be. Mac OS X, Solaris, FreeBSD.

Plus all the plugins. No one else comes close to touching all the plugins.
I work in a multi-platform environment, that's why I use Thunderbird.

The newest update (just released) has made it even faster, smoother with multiple accounts & even more intuitive.

In addition as a nice companion on my iPhone I use Webmail++ since it too, handles many accounts ever so easily.

I have seven accounts, Webmail++ is the only iPhone App that works so perfectly with that many accounts.
 
Im currently using mxHero and i have to say: i strongly recommend it. It has plenty features such as attachment trackin, self destruct email, private delivery or even choose when you send an email! best part is that is all in one, with a Chrome extension and for free. You should give it a go.
 
I use the built in mail client for my exchange account and sparrow for my gmail account.
 
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