What does the mail forward email option do?

A Mail Forward is a special mailbox that is setup to redirect all inbound email sent to that address to a email address on another domain name. This is different from a mailbox alias which is used to forward email to another mailbox on the same domain. This allows a user to collect email for multiple email addresses under one email central email account.

Example
The email user Bob is a web designer who creates web sites for other companies. Bob has his business email account as his primary email account, bob@designer.com. Every time Bob makes a new website for a company he asks them to create a mailbox forward of webmaster@company.com to forward to bob@designer.com so he can receive emails about problems with the website. Bob then only has to check his bob@designer.com email account for new mail instead of trying to collect email from multiple email accounts.

On the Weberz Hosting network mail forwards can be setup to forward their email to multiple email addresses located on any domain name. A good example of this could be a sales@domain.com email address which is forwarded to bob@gmail.com and sally@yahoo.com.