Is validation of the e-mail address required?

Do new users have to "validate their e-mail" to use ConfTool Pro?
What happens when users validate their e-mail addresses?

Validating the e-mail address is optional in ConfTool Pro. Users without validated e-mail addresses can also use the system, submit papers, do reviews and register for participation. So validation is not required to use the system.

Users without validated e-mail addresses will also receive confirmation e-mails and messages if you use the bulk e-mail function.

However, validating their e-mail address gives users read access to the submissions where they are listed as Co-Authors with their e-mail address.

Furthermore, the co-authored papers also get listed on the confirmation for participation and the invitation letter.

For further information on how to validate the e-mail address, please take a look here:
Co-author: How can I validate my e-mail address to access additional information in ConfTool?