need assistance writing simple command

so, i have 12,000 emails in a .txt file and they are in no particular order. I need to separate the the different email suffix's from one another but i am struggling on how to. using Gsheets i can sort by name, but there are to many common and i just get an oranized disaster i dont code but i found an area in google sheets that has a spot to write code.gs here is what i had for an idea (or what id like it to do)

    function myFunction() {
    if "inText:@gmail.com" = true
    move row to column B}

   {
   if "intext=@yahoo" = true
   move row to column C
}

ect. ect.

is there any way some one could help me? even if not with code, and just a way to seperate all the data in general

clicked almost everything in sheets, and googled quite a bit

    function myFunction() {
    if "inText:@gmail.com" = true
    move row to column B}

   {
   if "intext=@yahoo" = true
   move row to column C
}

i just hope some one can assist