I'll post this on Invites and Paper as well, but you ladies are my faves.

So we've decided to print the mailing envelopes. FI completely bashed my handwriting and begged that we please print them in a pretty calligraphy font. My cursive actually is pretty bad and unfortunately I'm the best bet we've got between the two of us hahaha. Anyway, now that I'm testing out how the envelopes will be printed, I realize I have no idea whether the mailing address should centered on the envelope or if it should be left aligned. What a silly thing to have to ask about but I've seen both versions online. So what is it? Left aligned, or centered? Or it really doesn't matter either way?
Examples:
Left aligned


Centered


Also, anybody have a clue how to print the return address on the back flap???
ETA: Ignore my retardness where I put "right aligned" in the poll, I defintely meant LEFT aligned. And nevermind on the back flap return address printing.. I've figured it out yay!