You can use the TRANSFORM>RECODE INTO DIFFERENT VARIABLES - but first you must extract the domain only and recode base on the domain.
Under TRANSFORM>COMPUTE VARIABLES, create a new variable using the function
Code:
CHAR.INDEX(<e-mail variable name here>,'@')
to create a new variable with the position of the @ (11th character, 4th character...).
After that, use the function
Code:
CHAR.SUBSTR(<e-mail variable name here>,<character index variable name here>)
to extract the substring with the domain only (@blablabla, @12345, @kkkkk).
You can also change the CHAR.INDEX variable and add a +1 after the function, so the domain variable will start after the @ (blablabl, 12345, kkkkk).