shell script argument parsing

Shell Programming and Scripting
1

how to parse the command line argument to look for '@' sign and the following with '.'.
In my shell script one of the argument passed is email address. I want to parse this email address to look for correct format.

rmjoe123@hotmail.com has '@' sign and followed by a '.'

to be more specific :

>abc.sh rmjoe123@hotmail.com

abc.sh should parse this email address and look for '@' and then '.'. If email address is valid, abc.sh should continue doing what it is doing. Otherwise abort with error message.

2 
echo 'a@b.com' | grep -q '.*@.*\..*'
echo $?
0

echo 'a@bcom' | grep -q '.*@.*\..*'
echo $?
1