Also this was done before by using a simple SQL find and replace query. Something like

UPDATE users SET user_email = REPLACE(user_email, 'old_value', 'new_value')

I removed<br>, and <u></u> tags, also transliteration symbols.

Could you please have another look to see if there are any other strange symbols!

I marked the status of the issue to "needs review". After your review, I will mark it as "fixed" and close it.