Python3 solution
Complexity\n- Time complexity: O(n)\n Add your time complexity here, e.g. O(n) \n\n- Space complexity: O(n)\n Add your space complexity here, e.g. O(n) \n\n# Co
# Complexity\n- Time complexity: $$O(n)$$\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity: $$O(n)$$\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution:\n    def numUniqueEmails(self, emails: List[str]) -> int:\n        myDict = set()\n        for e in emails:\n            local,domain = e.split(\'@\')\n            local = local.split(\'+\')[0]\n            local = local.replace(\'.\',\'\')\n            myDict.add((local,domain))\n        return len(myDict)\n```
['Python3']