How to add '@example.com' to multiple cells at once?

I have a column of 200+ cells of email accounts that do not have the ‘@example.com’ attached on the end. They are all listed in a ‘firstname_lastname’ fashion, and they are all hosted on the same provider. I would like to simply add ‘@example.com’ to all of the cells at once.

  1. Version 4.4.3.2, English, Calc
  2. Linux Mint 17.2, English

Hallo

Select the CellRange in Question and: →Edit→Search and replace

Search for .*
replace with &@example.com
with Options:
[x] regular Expression
[x] Selection only

Put ‘@example.com’ in a cell somewhere … say cell B2 for example
Lets assume your names are in column F beginning at F5
Insert a new column G or use the existing column G if it is empty.
At G5 put =CONCATENATE(F5, $B$2)
Then just copy this down the column to G205 or whatever the last row of names is.
You now have a column of email addresses!

CONCATENATE is the command which joins strings together.
Cheers