Yes, most services that link to your website should not be a problem. Updating DNS settings for services like Brevo or MailChimp is also within scope.
Unless we set up your email with our hosting, we won’t get involved in setting up your actual email accounts with Microsoft or Google as they are too complex to monitor remotely. However, changing the MX records with your domain DNS is covered.
The best thing is to chat through what you may require during onboarding. Over the years we’ve worked with many diverse systems, so can help with many. We will normally require you to set us up with a company email address, such as dev@yourcompany.com, and then set up an admin account with your supplier so we can quickly access their system if there is a problem. Otherwise, it takes too long to get login credentials.