RegEx with exceptions

Shell Programming and Scripting
1

I am totaly new to RegEx, but I need to extract emails with RegEx from text file

Some difficulties:

  1. �@�symbol has been substituted for � at �,"AT" or "(at)"

  2. I do not need any email with domain "myoldcompany"
    I found that with these I can found any emails:
    "^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$"
    How to do the following?

Thanks for any help.

2

The following seems plausible

^[^@]+@[Mm][Yy][Oo][Ll][Dd][Cc][Oo][Mm][Pp][Aa][Nn][Yy]$

Maybe your program (procmail?) is case insensitive or has such an option?