how to avoid to register the user with same email?
Can you be a little more descriptive on what you mean? Are you experiencing contacts with multiple contact records being created? Are you experiencing contacts that register for a campaign more than once?
I am assuming that you mean that you have a Infusionsoft web form where people register and are having problems with someone filling multiple forms or the same form multiple times with the same email, creating duplicates of their contact record. Please let me know if that is incorrect.
To avoid this you should go into your web form and go to the settings page. There you will see a section labeled “Duplicate Checking” where you can choose the option to look for. When someone registers and the criteria ( email, name, and email, etc. depending on the duplicate checking option you selected) it will update the contact instead of creating multiple contacts with the same information.
If the issue is somehow related to a bot fraudulently registering and using the same email you can enable the “Spambot Detection” option in the settings tab to avoid that as well.
Please let me know if I can be of any further help.