First, anyone with an osu.edu E-mail account and a departmental account needs to forward their osu.edu E-mail to their local (ChBE, MSE, etc.) account. The best way to handle this is to use this form. The main reason for setting things up this way is so you don't have to check two different accounts for your OSU-related correspondence. It also makes sense to use the departmental mail server as your main "message store," since you have a vastly larger file space quota here than on the osu.edu servers. The osu.edu mail servers limit any message to 10MB and total file space to 30MB for faculty/staff, and 15MB for students. The departmental mail server provides 5GB of file space to all users and has no arbitrarily imposed message size limits.
Due to the aforementioned message/space limits imposed by the osu.edu mail servers, it makes little sense for local users to forward their E-mail to their osu.edu accounts. What's more, by choosing to use a non-local mail server to read your departmental mail, the departmental mail server will not be tracking your last access time. As such, your local account will be marked "inactive" after 180 days and any departmental mailing lists on which you're typically listed will have your address removed. So, by forwarding your E-mail to a non-local server, you could very well miss out on important information.
So, which E-mail address should you use? In your E-mail client software (e.g. Eudora, Outlook Express, etc.), your departmental E-mail address should be specified as the return address. This is especially true when you're forwarding your osu.edu E-mail to your local account; if you were to specify your osu.edu E-mail address as the return address as you send to another local user, the message has to hit the osu.edu mail server, then come back to our server for the recipient to read it. If the recipient then replies, the message has to go back out to the osu.edu server just so it can come back to the local server. There's also the message size limits and file space quotas on the osu.edu mail servers to consider: why artifically impose such limits on replies to your messages by specifying your osu.edu address as your return address when you could completely circumvent these issues by merely specifying your departmental E-mail address as your return address?
There are times when specifying your osu.edu E-mail address is appropriate or even preferred. OSU designates your osu.edu E-mail address as your "published" address. So, it's completely proper to cite your osu.edu address in print and during conversation (such as over the phone). When you do so, you should warn folks that when they send a message to this address, you will reply (if necessary) from your real E-mail address, which your prospective correspondent should use thereafter. When you are signing up for various services online, especially if you don't have a personal E-mail account (like Hotmail, Yahoo, or from an ISP), you should specify your osu.edu address when requested. If you are coming from another institution or the business world, and you want to set up forwarding from your previous place of education/employment, you should specify your osu.edu address in these cases, too. Much of the reasoning behind using your osu.edu address revolves around efficiently handling spam, when it occurs. As this documentation was prepared, the anti-spam measures employed by the osu.edu servers are more powerful than those of the local mail server. As such, in cases when you're not sure what providing your E-mail address might lead to, it's best to have these anti-spam measures available to you to act as a "shield," should someone to whom you provide your E-mail address abuse it.
If you have access to a personal E-mail account (via Hotmail, Yahoo, or some other external provider, including an ISP), you should specify that E-mail address for purely personal issues, such as entertainment. Any E-mail accounts you have within OSU should be reserved for communication related to academics, business and/or research here at OSU whenever possible.
If you have any questions or suggestions for clarifying this information, please feel free to contact ECR6 Management.