Anything much bigger than a legal-sized envelope will be summarily tossed, as will anything that isn't pre-approved. We're big believers in recycling; anything unsolicited is SPAM unless proven innocent.
Send an email for permission ... address supplied only if you have a GOOD reason!
Same rules apply: clearly label "PsiWriters" in the subject line. Attachments will NOT be opened, so don't even bother. Again, it's SPAM unless proven otherwise!