One way, using a formula:

=MID(A1,FIND("@",A1)+1,256)

To do it in place:

Choose Data/Text to Columns/Delimited, click Next. Check "Other" and
enter "@" in the input box. Click Next. Select the first column and
select the Do Not Import Column (Skip) radio button. Click Finish

In article ,
Pete wrote:

Delete data in a cell before the @ sign in an email address