Are spaces allowed in an e-mail address?
Spaces are not allowed in an e-mail address without quotes being added. Because of this limitation and lack of support, spaces are rarely used in an e-mail address.
It is more common to break up an e-mail address using a period. For example, John Smith may have an e-mail address: [email protected] or [email protected].
Using quotes
Spaces can be added to an e-mail if quotes surround the first portion of an e-mail address. For example, the following e-mail address has a space separating "email" and "example" in the username portion of the e-mail address is technically valid.
"email example"@computerhope.com
Not all websites, e-mail services, tools, and e-mail programs support this ability. So, while it's technically possible to add spaces to an e-mail address, it's not recommended.
If you need a more complete technical explanation of the format of Internet messages, see RFC 5322.