When using a catch-all or multidrop POP3 mailbox, the original recipient addresses may be stripped by the mailing list server before POPcon receives the message. This is an inherent limitation of catch-all mailboxes.
Solutions
- Check email headers: POPcon searches multiple header fields (X-Original-To, Delivered-To, Received, etc.) for recipient information. Review the email headers to see if any recipient field is preserved.
- Use individual mailboxes: Set up a dedicated POP3/IMAP mailbox for the mailing list subscription. POPcon will deliver to a single address, avoiding the detection problem entirely.