How do you get mail if your Sims are never at home?

Go into build mode and add a mailbox to the retail lot.

Sims can use any mailbox anywhere on any lot. I always add mailboxes to commercial venues so my sims can use a mailbox if needed, no matter where they are.

OMG, I didn't know that! Thank you so much!

You're welcome! I'm now picturing you running around adding mailboxes everywhere... :D