Need suggestion regardig Spam policy.

[Prem of Pondicherry]

Hi Guys/Girls

We r getting lot of spam(unwanted) messages like porn-advertisements,
commercials etc.

Please suggest if I need to
(1) Make subscription based on moderator-approval (i.e no more open
subscription)
(2) Monitoring each mail before allowing for post [a tedious task]

Thankyou members

Cheers
Moderator