It seems possible that Nigerian Internet cafes are full of emailers with names like Mr. John Richard who use yahoo email addresses and who come from a culture where it is common to write subjects in ALLCAPS. When they write to people they don't know, they -- quite sensibly -- start mails apologizing for the fact that they may have surprised their readers with an unannounced missive. Spammers and scammers put all these more upstanding folks at a real disadvantage
Reminds me of the mail I received recently at openmikes.org, from a young singer/songwriter just starting out, looking for a place to play. She titled her mail “18, New and Frightened”. Sheer chance that I actually glanced at the message content rather than dumping it straight to the “missed-SPAM” folder.