I've configured email using $wgSMTP, but when I send an e-mail to another user, my $wgNoReplyAddress is used instead of the e-mail address the user set.
Topic on Project:Support desk
User-to-user e-mail return addresses
You need to set $wgUserEmailUseReplyTo in order for from address to be another user. Note there may be some problems with doing this and spam detection, (from code comments):
// Put the sending user's e-mail address in the From: header. // // This is clean-looking and convenient, but has issues. // One is that it doesn't as clearly differentiate the wiki mail // from "directly" sent mails. // // Another is that some mailers (like sSMTP) will use the From // address as the envelope sender as well. For open sites this // can cause mails to be flunked for SPF violations (since the // wiki server isn't an authorized sender for various users' // domains) as well as creating a privacy issue as bounces // containing the recipient's e-mail address may get sent to // the sending user.