best regards; pleased to meet you; please remember me; please treat me favorably (favourably); please take care of
メールの最後に４６４９と添えた。
I added 4649 at the end of the email.
４６４９は語呂合わせで「よろしく」と読む。
4649 reads as 'yoroshiku' through wordplay.
車のナンバーが４６４９の人を見かけた。
I saw someone whose car number plate was 4649.