Thank you very much for your suggestion. I actually will use a combination of your code with a slight modification and the code that Hilmar suggested earlier.
I need to do this in case the “ “ is an only delimiter, and then by using your code it would replace it with an empty string and will result in an incorrect address.

lcDelims = ",:/" && all the delimiters you want changed
lcChangeTo = ";"
lcEmail = ChrTran(lcEmail, lcDelims + " ", Replicate(lcChangeTo, Len(lcDelims)+1))
do while ";;" $ lcEmail
lcEmail = StrTran(lcEmail, ";;", ";")
enddo

Thank you again to everybody
Yelena