The regex you've given does
not require a letter. In every regex implementation I've encountered where \w has meaning, it will match (as a minimum) [0-9A-Za-z_] - some implementations will also match accented/etc letters, but they all match at least those 53 chars.
But what's the context of this?
To correctly validate all email formats with regex is actually a hugely complex task (due to what syntax is allowed by various email software), and it's probably not worth the effort to do more than check that there's a single @ and at least one dot.
Which is usually easier to do with simple text checks:
code:
if ( Text.contains('@') and Text.contains('.') )
But if you're forced to use a regex for something then:
code:
[^@]++@[^@]+.[^@]+