noatime

If you need I/O performance bust it might worth to turn on noatime flag on important partitions. Look down to see how it pushed down the read level on a server with Apache serving a static content.

Usually I add noatime flag during a system installation, but this time forgot about it and had to remount the file system. Thanks that mistake I got this beautiful image ;)
You can go even further and turn on nodiratime, it should decrease read even more.

GMAIL and msmtp (Mutt)

This is the example how to configure the msmtp (i.e. for Mutt) to use thegmail smtp server. Remember that you need the certificate. I have got mine from old Ubuntu installation (Saving /etc directory before reinstallation a box is good idea).

account your.user
logfile ~/.msmtp.log

tls on
tls_starttls on    
tls_trust_file /etc/ssl/certs/ca-certificates.crt
auth on

host smtp.gmail.com
port 587 
from your.user@gmail.com
user your.user@gmail.com
password YOUR_password

BTW, in Ubuntu you can grab certificate by sudo apt-get install ca-certificates.