How do I make an Excel Data Validation to check E-mail address formats?

I've been asked to make an excel book that has a validation in it to check e-mail addresses. They want the validation to check for a few things, and I can't get it to work for all of them at once. When someone enters an e-mail into the cell, they want excel to check for: -The email to contain at least... show more I've been asked to make an excel book that has a validation in it to check e-mail addresses. They want the validation to check for a few things, and I can't get it to work for all of them at once. When someone enters an e-mail into the cell, they want excel to check for:

-The email to contain at least one period (.)
-The email to contain one 'at' symbol (@), BUT no more than one @ symbol

So far I can get Excel to check that the symbols are there, but I can't get the error message to show for if there's more than one @ symbol. I'm using this formula:

=AND(FIND(".",A1),FIND("@",A1))

Any ideas on this? Thanks in advance!
3 answers 3