title: Delphi: validate email without regular expressions
body: <p>Since Delphi does not have any regular expressions library built-in, have you seen a good function to validate email addresses at least to some degree in using only Delphi RTL/VCL? </p>
  
  <p>I don't want to link additional *.dll to my product integrating regular expression support and I need also Delphi 7 compatibility. Embedding regex library into exe increases it's size and I doubt it worths adding next 100k because you just need 10-50-lines function of email validation.</p>