I can't remember much, but hopefully this is specific enough to jar someone's memory. In this novel, the method of travelling to other planets involved something like cloning. The original person would stay on earth while a copy was essentially faxed to another planet and created to start a new life. Obviously there were laws against ever coming back, so that you wouldn't have clones of yourself on the same planet. The protagonist of the book somehow did end up coming back to earth and meeting himself, which was not the main plot point but was a major problem in the second half of the book. I think I read it in the 1980s, but it could have been an older book. Does this ring a bell with anyone?
The only other thing I seem to remember is the main character (who was male) met someone he knew (a woman) at a dinner party which led to the duplication being discovered. Pretty sure the book was 80s/90s at the latest and I'd say it had more of a 60s feel.