Newbie using Postcards for Direct Mail

[David Elefant]

Hey All,

My partners and I have done 3 rounds of direct mailing using envelopes, but are starting to expand and are looking at the possibility of using postcards due to the price difference. From our understanding, postcards aren't usually sent with envelopes, but we're not sure if there is a legality issue with sending out personal information like that without being enclosed in an envelope. Any feedback would be great, thank you!

-David Elefant