If you are just trying to find everything after the @ character, that is very doable with formulas.
We can start with the FIND formula to find the location of the @ character in the string.
=FIND("@",email_variable)
This returns the index position of the first @ character in the string from the email_variable. The downside here is that is the email_variable is blank or doesn't include an @ character, it will give an error, which is less than ideal. One way around that is contatenating an @ character to the end of the email_variable to ensure it always has at least one @ character.
=FIND("@",email_variable&"@")
Now we know the position of the first @ charater in the field. From that, we can use the MID formula to get everything from that character and after. We actually want everything from 1 position after the @ character, so we can add 1 to the FIND formula's result. That gives us the start of the position to pull out of the string, and then we just need to get the end, which we can just make a wide assumption and say 999 or some other number that we know will be well after the end of the string. Put it all together, and it'll look something like this:
=MID(email_variable,FIND("@",email_variable&"@")+1,999)
The formula now returns everything from after the @ character in the email address.
And because we took the added step of adding the extra @ character to the end of the string, we don't get an error from the formula if the email doesn't have an @ character within it - because the formula is actually working, it's just grabbing everything after the end of the string.
I hope this helps. Have a nice day!
P.S. - you should probably edit your post and change it from a Discussion to a Question, so that you can mark it as Answered when you have a solution you like.