you can use varchar as your data type for email column as emails are usually composed of letters, numbers and special characters. The right value of data lenght for the email field is database-agnostic. If you are also considering standard SQL types, the same can be said for data type, that is a string.

What is type of email in database?

VARCHAR is the best data type to be used for email addresses as Emails vary a lot by length. NVARCHAR is also an alternative but I would recommend it to use only if the email address contains extended chars and keep in mind that it requires double amount of storage space as compared to VARCHAR.

What data type is an email in access?

There is no specific datatype for email, so your only options are to either create a validation rule for the field that checks your entry is correct, or, the best way to do it would be to validate your email in the user interface itself.