I've installed Ubuntu onto my on-the-go laptop. I end up sending and receiving mail often, and sometimes quite quickly with people replying immediately. I have two accounts, one of which is my hotmail (outlook.com) account which I actually use most often and are IMAP connections.
I've tried Geary, Claws, Evolution and now I'm using Thunderbird.
The problem here is that I want to be notified immediately when I get a new e-mail so that I can quickly reply, and I can receive quick replies right away without having to keep pressing "Get messages".
Outlook.com does support push mail notification because I get it on my phone. If I send myself an e-mail, I get instant notification on my phone. However, this is no good when I'm roaming and my data is off, and working from a hotel room, or I'm working in an area that doesn't allow cell phones.
I know that I can set Thunderbird to check every 1 minute, but sometimes I'm literally only online for 2 minutes reading, replying and reading e-mails.
tl;dr
How can I get push mail on ANY Linux client? I've been googling and just can't find an answer for Linux. I would also be happy with a separate notification program that just tells me there's new mail so I can hit "Get Messages".