Please note - I have only tested them on the email format you have supplied. If you have any other formats ( e.g. email@example.com ; firstname.lastname@example.org etc ) then you will need other formulas. If there are a lot of different amila address ormats then I'd suggest using a VB script to check the format & then apply the correct sets of formulas.
Something else you could do, a 2 step process manually, is to select your cell with the e-mail address. From there select Text to Columns from the data menu. Type in a decimal (.) in the "other" delimiter field. You can change the destination to the cell beside the original if you want to maintain the source. This will parse in to (3 in this case) columns.
Repeat the process and change the delimiter to the @ sign. In my try, i left the destination as the same cell and overwrote the cell containing the com entry as you indicated you did not want the com in the output.
If you recorded a macro to perform both steps, you could automate the process greatly and have it available at any time.