I wouldn't worry about the post card, given that the point of it is just to let you know that they'ge got your ms. It's actually quite nice that they do that, rather than just go "post us the ms and we'll call you". Putting a stamp on it yourself is probably a good idea, not everywhere will pay postage.

Lawful Neutral (1 point away from Lawful Good) Human Cleric, 3rd level, STR 13 DEX 12 CON 13 INT 16 WIS 15 CHA 13. I want more options in the questions.