The domains are currently in u：
—For business，ercial enterpris，or online rvibsp;like Ameribsp;Online.Most panies u this extension.
edu—For educational institutions and uies.
gov—Rerved for United States gover agencies.
—For works；usually rerved for anizations subsp;as I rvibsp;providers.
—For non-ercial anizations.
For the tents of e-mail，there are usually two parts，the header and the body.The header tains the name and address of the recipient，the name and address of anyone who is being copied，and the subjebsp;of the message.Some e-mail programs also display your name and address and the date of the message.The body tains the message itlf.
paratively speaking，e-mail has the following strong points：
·It bsp;be as fast as telex and fax.
·It is cheaper than an iional phone call，fax，and telex.
·The message and attat bsp;be nt easily.
·Some of e-mail address bsp;be applied freely.
·It is 24-hour rvibsp;and the message bsp;be received unattended.