Greg Earle earle@isolar.dyndns.org writes:

Obviously I've changed the account password but I would really like to know how they were able to create e-mails on my system when ostensibly I would have assumed they could only read the account's e-mails via IMAP.

The INBOX is not read-only. There's nothing really special about this mailbox versus other mailboxes. IMAP is used to create messages all the time. For example, if you have an outgoing "Sent" folder, once your mail reader gives it to your mail server, it then puts a copy into the outgoing folder via IMAP. Once someone gain controls over your IMAP account, they can create messages with a format totally different than what your mail server can make.

Joseph Tam jtam.home@gmail.com