Questions

Email Forwarding (re-direction) is when email sent to one email address is transferred to another email address.
If you have site Hosting or a Domain name with Netcells, you can set up your own Email Forwarding and change it at any time in your site's Control Panel (cPanel) - go to >Mail>Forwarders AND/OR >Mail>DefaultAddress (not Email Domain Forwarding - unless you want to mirror all mail settings on your domain and sent all coming mail to corresponding addresses on another domain - info@mydomain.com will go to info@someotherdomain.com if such address exists).
If you are receiving a lot of spam (junk mail) you should set your forwarding FROM a SPECIFIC address (Example 3), rather then from a Default Address (Example 2).

Remember that:
[1] the address you are forwarding TO has to be currently active (and the recipient has to have access to it).
[2] you will not be able to read the email on your server as it is passed through to another address.
[3] when recipient replies to forwarded email the reply will have the destination's return address - unless the recipient has it set differently or has multiple identities.

Example 1:
You have a domain mydomain.com.
Set up email for your partner - partner@mydomain.com to be forwarded to somename@someaddress.com.
All email sent to partner@mydomain.com will be passed through your server (you will have no access to it).
Your partner will always get mail sent to partner@mydomain.com even if he/she changes their own destination address (in which case, you will need to re-set the forwarding address).

Example 2:
You have a domain mydomain.com.
Set up ALL and ANY email coming to mydomain.com to be sent to someaddress@myothersite.com
You do that in Mail>DefaultAddress

Example 3:
You have a domain mydomain.com.
Set up email coming to me@mydomain.com to be sent to someaddress@myothersite.com or me@myinternetprovider.com
You do that in Mail>Forwarders
Set the Default Address in Mail>DefaultAddress to :blackhole: (this is done by default on new accounts).
This settings will destroy all spam (and any other mail) coming to mydomain.com EXCEPT mail coming to me@mydomain.com

Instructions on how to access your Control Panel (cPanel) is explained in FAQ9.