~/.muttrc: Use an aliases/addresses file

But I haven't used mutt itself in ages...

.muttrc

@@ -8,6 +8,9 @@ set postponed="+postponed"
set record="+lu/INBOX.Sent"
set sleep_time = 0 # faster mailbox switching
set alias_file="~/.addresses"
source ~/.addresses
mailboxes +lu/lu \
          +lu.sprd/lu.sprd \
          +htwk/htwk \