What data type is Blynk.email

Hello, i need to know the data type of Blynk.email, i know just do this “data here” but i want to pre define it and i cant seem to do it Sting or char doesn’t work and i don’t know what other data type it could be, thanks

like this:

Blynk.email(String EMAILtemp,String NAMEtemp,String NAMEtemp);
or
Blynk.email(char EMAIL, char NAME, char NAME);

they return errors like this:

exit status 1
no matching function for call to 'BlynkWifi::email(String&, String&, String&)'

The variables are Strings so for example:

String EmailCustom    //or  char EmailCustom[40]
String EmailSubject    // or char EmailSubject[20]
String EmailBody or   //char EmailBody[60] 

Blynk.email(EmailCustom, EmailSubject, EmailBody);

Default is a maximum of 120 characters in total for email address + email subject + email body.
This can be increased as indicated in the comprehensive Blynk documentation at http://docs.blynk.cc/#widgets-notifications-email

Have you added the Email widget to your project?

Yes i have, the errors occur with compiling the sketch so i will try that see if it works