Different people can send the same sequence thanks to Shared Sequences. Often, the goal of the sequence is to book a meeting with the recipient. You want to book the meeting on the sender's calendar, not the sequence creator's. You can do this using the {{sender calendar url}} variable.
When you create your sequence, start typing the curly brackets {{ or click the Insert Variable button and add the {{sender calendar url}} variable.
Each Mixmax user can specify a Calendar to use when they send a sequence (or any email) with the {{sender calendar url}} variable. Go to your Calendar Settings page and scroll til you see the Default calendar URL. In the drop-down menu, select the Calendar you want to use for your default calendar. If you don't select a Calendar, Mixmax will automatically default to the Calendar at the top of your list on the Calendars page.
Using a Rule, you can also use the {{sender calendar url}} variable in sequences you trigger to send. For example, when a Salesforce Opportunity is created, you can trigger a sequence sent from the Opportunity Owner.