Q:

Mass email the Visualforce email template

We have a limitation using Visualforce email template. VF Email Template can't be used for mass email.  
I am look for the ways how this can be achieved.   
I have created a visalforce email template which displays the opportunity records based on Used If in the tabular form on the email.   
Next is i need to send this email template to all the users on every last week of the month.When the mail is sent it has to capture the User id and display the records.  
My question is how to send an mass email using Visualforce email template to all the user on the last week of the month.   

A:

Not the exact solution you are looking but a workaround might help
From the doc Visualforce email templates cannot be used for mass email
So - how to get around this?

You will need to use a custom field, Workflow email alerts + field
update In your trigger or VF controller, 
when the affected record(s) are ready to have their mass email sent,
    mark custom field is_ready_for_mass_email__c to true
The workflow
    will execute upon the batch of updated records
The object's fields
    can be used as merge fields for the VF template
The workflow then
uses a field update to set is_ready_for_mass_email__c to true

Of course, the recipient will need to be a field of type Email in your object so the email alert has somewhere to send the message to.

