Posting to your WP blog by email is cool and handy. Using the standard post by email setup isn’t, with the chance of ANYTHING sent to the designated email being automatically posted. Not cool. Here is how I sorted it with gmail….
Create a gmail address you want to use exclusively for posting content on your blog
Set up the filter to only accept email from a designated email address (See here about how to do this) This is truly clever.
Setup the Postie plugin in WordPress
Mail protocol – IMAP-SSL
Use TLS – NO
Port 993
Mail Server – imap.gmail.com
MailuserID – theaddressyoucreated@gmail.com
Mail password – whateveryousetaspassword
Delete mail after posting – YES