Goodbye Opera, Welcome back my Beloved Firefox Web Browser

I'd used Opera from May of 2008 to March of 2010, against my strong philosophy of open-source software use.

Flush a queue of e-mails

For various reasons it's possible that some e-mails are queued (for instance because of issue into an element of a full and safe emails server - e.g. too old packages, broken anti-virus, broken anti-spam ...).

After having fixed the issue, it's interesting to flush all queued e-mails, which can easily be done with the following command:
postqueue -f

Stop updating packages as often

When managing computer administration, there is a big trap to avoid: update the packages as soon as they are available.

Stop polling for incoming e-mails

Unfortunately, it seems there are lots of us (computer users) polling for incoming e-mails very, very often; like if a very important thing might be received and to be answered almost immediately.

Help ! rpm or yum freezes

Sometimes, rpm, yum or even other commands are freezing without message to understand why (e.g. for yum, just after the message "Running Transaction Test").