Looking for mail client that allows different IMAP and SMTP servers

[mahesh]

I have a Mac and use Apple Mail for sending mass amounts of emails. I got a Linux computer for traveling and want the same setup described below:

My email is a Gmail address, but I use SendGrid as my SMTP server to send out a large amount of emails (Gmail only allows 500 emails per day). Apple Mail lets me have Gmail IMAP settings for incoming mail, and lets me set SendGrid's settings for outgoing SMTP mail. But I can't find a client that easily does this for Linux.

I tried Evolution but it doesn't give me a place to enter unique login details for the SMTP server, it only lets me put a username but no password. Thunderbird was crazy slow. Was wondering if there's another app out there?