There are 2 places from which you can send bulk emails and smses.  The Age analysis screen and the SQL Query screen.  Either of these will allow you to select the correct group of accounts, after which you can compose your message and send to all the selected recipients.

WARNINGS: 

  1. Sending bulk emails for any purpose other than sending accounts or following up debt is illegal and at best likely to have your email account blocked as a spammer.  Any marketing messages must be sent via a 3rd party email utility, like Sendgrid or MailChimp, which complies with all the privacy and opt-out regulations. 
  2. Even when sending bulk accounts make sure to send them in small batches (+_ 10) from the outbox and if there are over 100, spread them out over a few days.  This will minimise hassles with your email service provider.
  3. There are no such limitations when sending bulk SMSes so that you should use this option whenever possible.  But make sure you stest your message on your own cell number first before sending to everyone.  Also make sure you have enough WinSMS credits. Note that long messages might use 2 or more credits.  WinSMS