1. Ask youself what you actually want.
2. Imagine the query.
3. Write the code.

somethingElseModel::with('email')->where('stuff', $stuff)->get();

No, there's no such thing. Luckily you can do it by yourself with no effort:

/**
 * query scope withWhereHas
 * 
 * @return void
 */
public function scopeWithWhereHas($query, $relation, $field, $operator, $value)
{
	$query->with([$relation => function ($q) use ($field, $operator, $value) {
		$q->where($field, $operator, $value);
	}])->whereHas($relation, function ($q) use ($field, $operator, $value) {
		$q->where($field, $operator, $value);
	});
}

// then for example:
$something = Something::withWhereHas('someRelation', 'someField', 'like', '%someValue')->get();