If your organization schedules an Advanced Mass Email to run at a future date and time, you may have noticed how any changes or modifications made after the time of the scheduling are NOT reflected in the resulting mass email... For example, let's say that you scheduled a mass email to be sent out next month. Once you've scheduled this future mass email job, any changes that you make to the template used when scheduling this job will NOT be reflected in any mass email scheduled prior to saving those changes. Similarly, if you go in and change the email address for an account who is set to receive an already-scheduled mass email, the scheduled mass email will not recognize that update. Scheduled mass emails always send to the email address associated with an account at the time of the scheduling.
Try to think of a scheduled Advanced Mass Email as being a "static" process... In other words, when you schedule a mass email to send out at a later date and time, eTapestry essentially takes a snapshot of your email template and your list of recipients (i.e., emails for each account included in the query selected) as they are at that precise moment. Then, this information is immediately dispatched to our third party email vendor (Delivra), where it awaits in a queue to dispatch at the exact date and time indicated when this email was scheduled. Therefore, any updates or changes made to anything connected with this scheduled mass email job (either the template or the accounts that are set to receive this email) will not be reflected in an already-scheduled mass email job.
If you would like to make changes to anything involved in a mass email job that has already been scheduled for a future date (including email addresses associated with accounts in the query used as the recipient list), be sure to cancel the existing scheduled mass email job so that you can make any desired changes and save those changes before re-scheduling the mass email.