At the moment Influencer Outreach tool supports GMail and Outlook365.
"I have a Google account, but I receive an error when I'm trying to connect it to Influencer Outreach. What should I do?"
In case you receive an error mentioned above, it means GMail is turned off on your Google account. Therefore, there are several ways you can solve this problem:
If you have a corporate account, you can ask your administrator to give you an access to GMail service. Please check the following article for more details: Turn Gmail on or off for users
Try using another account with a GMail access turned on.