What is Email Hijacking?
Email hijacking is an issue typically occurs when a spammer uses a script utility, initiating what's called a Dictionary Attack, and is able to guess a users email password. This occurs most often when a user has set a simple password that is easy for spam utilities to guess such as "testing" or "abc123".
Preventing Email Hijacking
To help avoid email hijacking we recommend that all email account users implement strong passwords that will be difficult for spammers to guess.
We recommend that you review all of your email account passwords and implement strong passwords. Please reference the article below.
http://www.microsoft.com/protect/yourself/password/create.mspx
WebFX has also be upgraded the hosting control panel application which now includes a feature that forces an email user to assign a stronger password for a new account. The new tool has certain limitations so it's up to you to implement strong passwords on all of your accounts.