The sendMail method allows you to send emails to unlimited number of recipients. For example, in Samigo when you publish an assessment if you check (notify students) you send an email to all the students, and that number could be greater than the maxRecipients you configured in ETS.
Choose a site with more students than maxrecipients value (by default 100).
Go to Samigo and choose/create one assessment to publish it.
In the publish screen choose send notification option and click publish.