E-Mail Trigger
The E-Mail Trigger allows you to retrieve e-mail messages from POP3 and IMAP servers and trigger a job if messages match filtering rules (based on properties such as message contents, message headers, and attachment names). You can also save the messages and/or message attachments to disk for processing.
The E-Mail Processing Task and the E-Mail Trigger both offer exactly the same functionality, except that the E-Mail Trigger triggers a job when it finds messages that match the selection criteria, while the E-Mail Processing Task must be included in a job that is triggered through some other mechanism.
For example, if you want to run a job each time an e-mail message arrives, you would use the E-Mail Trigger. If instead you wanted to run a job at 6:00pm to process any messages that have arrived during the day, you would use a Schedule Trigger to run the job, and an E-Mail Processing Task to download the messages.