To my knowledge, the users will only recieve an email if Moodle has to generate a password and notify them (when doing bulk upload).
If you are using an auth-service like SAML2 then you won't need to store the passwords in your Moodle platform, so passwords won't be generated and no notifications will be send.
If you upload them with passwords, moodle won't have to generate passwords, and will therefore not notify them.
If all the users you need to reach has been added to the same course, and your message settings is to send them an email if they are offline, then you can reach them all by going to course -> participants -> Select all -> Send message.
From there you can also easily download a .csv file with their emails, and use your own mail client, if your settings isn't set to send them mails with messages.
If you are using an auth-service like SAML2 then you won't need to store the passwords in your Moodle platform, so passwords won't be generated and no notifications will be send.
If you upload them with passwords, moodle won't have to generate passwords, and will therefore not notify them.
If all the users you need to reach has been added to the same course, and your message settings is to send them an email if they are offline, then you can reach them all by going to course -> participants -> Select all -> Send message.
From there you can also easily download a .csv file with their emails, and use your own mail client, if your settings isn't set to send them mails with messages.