I guess, it means that you must escape the character '-'
by writing '\-'
within the regular expression, when it’s not used as a range indicator.
Try to change:
'.+@^[A-Za-z0-9.-]+\.^[A-Za-z]{2,4}'
by
'.+@^[A-Za-z0-9.\-]+\.^[A-Za-z]{2,4}'
As @Fallenhero stated. The '^'
seem also to be misplaced somehow.
1
solved The regular expression error is malformed