Most such functions in OE are setup and managed at Tools|Message Rules. To send your friend's mail directly to the Delete box, the normal "rule" would be addition of the sender's address to the "Blocked Senders List," although you can use other kinds of rules to accomplish the same thing, if the mail protocol you're using permits local rules at all.

Since you can block an individual sender or all messages from a particular server, or even from a particular domain, etc., it's possible that some other sender (spammer?) that you blocked was blocked at a service level that's shared by the friend - perhaps.

Almost everything in the rules section is by adding or deleting checks in little boxes, so it's hard to mess anything up. To be super-cautious, making a written list of any changes you make, as you poke about, should let you undo any damage, so it's fairly safe to look into what's there.

Rules generally do NOT work in OE if you're receiving http or IMAP mail, (POP3 is the "usually preferred" protocol for OE) but your email service can redirect mail - downloading it to you but putting it directly into the bulk mail or deleted mail box, if filters that the service provider applies detect "suspicious content or origin."

If you don't find anything suspicious in the Tools|Message Rules, your friend may have a bug in email being sent, and/or the server or domain the friend sends from may have been tagged as a source of high volumes of spam and is being diverted by your email service.

Often spam volumes high enough to get a server tagged are the result of someone using the service with an infected machine that's being used as a "bot" to send spam without the machine owner's knowledge. The infected machine(s) could be your friend, and/OR anyone else using the same server.

If your service is doing the diverting, you may or may not be able to get them to explain what/why it happens; but if you're reasonably sure that nothing on your machine has been changed it probably is worthwhile to try to contact them and ask, or at least to look for a FAQ page at the service's site for clues.

John