Regards,
Thanks and regards,
(You should spell out "and" rather than using the ampersand -&-)

Dear Teacher,
Please let me know which of the folloiwng is correct (punctuation) in letters:
1) Regards, or Regards.
2) Thanks & regards, or Thanks & regards.
Sweetie.
Regards,
Thanks and regards,
(You should spell out "and" rather than using the ampersand -&-)