Question

I need to validate email addresses which can be single or several comma-separated ones.

Before I was using in a regular expression validator an expression like:

string exp = @"((\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([,])*)*";

and it was validating multiple or one single email address.

But same expression is not valdiating in C#? It says valid to invalid addresses as well.

Please correct me or suggest me an expression to validate email addresse(s).

Answer 1

Please give more details. Which addresses are matched as valid, but should be invalid? How do you call the regex (your c# code)?

A point I see is that you are missing anchors.

 ^((\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([,])*)*$

^ matches the start of the string

$ matches the end of the string

If you don’t use them your pattern will match as soon as it found a valid sub string.