=/*  Email Address Validation for Appian 7+  */
  /*  Allows the 'name' to contain letters, numbers, plus period and special characters: _ - + ' & %  */
  /*  Allows the 'domain' to contain only letters, numbers, period and dash.  */

if(
  or(
    len(trim(ri!address)) > 255,
    length(split(trim(ri!address), " ")) > 1,
    length(split(ri!address, "@")) <> 2
  ),
  false(),

  with(
    localPart: split(trim(ri!address),"@")[1],
    domainPart: split(trim(ri!address),"@")[2],

    if(
      or(
        length(split(domainPart, ".")) < 2,
        contains(split(localPart, "."), ""),
        contains(split(domainPart, "."), ""),
        not(isnull(stripwith(lower(domainPart), "abcdefghijklmnopqrstuvwxyz1234567890-."))),
        not(isnull(stripwith(lower(localPart), "abcdefghijklmnopqrstuvwxyz1234567890-._+'&%")))
      ),

      false(),

      true()

    )
  )
)