Ending your letter with best, all the best, all best, or best wishes indicates that you hope the recipient experiences only good things in the future. Although it is not quite as formal as sincerely, it is still acceptable as a polite, formal/semi-formal letter ending, proper for business contacts as well as friends.
It's more an expression that you hope all goes well in their life. I've also seen "All the best" used as a way of signing off in an email or letter (instead of "Sincerely" or "Best regards"), although it is not overly common. It would be strange to use "best of luck" here.
Goodbye is used as an everyday term usually when two people are ending their interaction (or it maybe used as a short time) while farewell is more formal and usually implies that you will never see the person again (or it will be a long time).
An Irish Goodbye is a term used to describe leaving a social event without saying goodbye to anyone. It is also known as an Irish Exit, Dutch Leave, or French Exit. This practice has become increasingly common in recent years, especially in the age of smartphones and online dating.
You can say 'All the best' when you are saying goodbye to someone, or at the end of a letter or an email. Wish him all the best, and tell him we miss him.
It is just a general salutation to wish that whatever it is goes well or will happen in the best way possible – favoring that the best among all the things happen. Similar to “Farewell”. Some may deem it to be more formal.
Other Ways to Say Goodbye
Farewell – This is a formal way to tell someone to be safe while they are away from you. Cheerio – not generally used in the United States but it is another friendly form of goodbye. See you – This is a more formal way of saying 'see you later'. Used more in a formal sense or workplace.
“The easiest way to find out how you feel about someone. Say goodbye.” “Life is made of so many partings welded together.” “I don't have to be so afraid of goodbye, because goodbye doesn't have to be forever.”
"All the best" should be used when you're saying farewell to someone (usually when they've got a new job or something that means you may not see them again). "Best of luck" should be used when you simply want to wish someone luck at that very moment.
As long as you are wishing your recipient the best in their future, it's acceptable to use the phrase both as a universal sendoff and as a more personalized ending.
The phrase "wishes you all the very best" is a correct and usable phrase in written English. It is typically used as a way to offer good wishes and encouragement to someone. For example, you might write: "I hope this new chapter of your life brings you joy. Wishes you all the very best!".
All the best
It can be used in professional or informal writing. It invokes a sense of kindness that you are wishing them all the best, but it's shorter than saying "I wish you all the best". Use this if you don't need to be overly formal and are ok with more of a relaxed tone with the person you are emailing.
Don't Leave Without Saying Goodbye. Tempting though this may be, especially when your hosts are surrounded on all sides, it's essential to say thank you to your hosts on the way out the door. If they are speaking with other guests, wait until you see a pause in the conversation, and then say your farewells.
An Irish goodbye is when you abruptly leave a party without telling anyone.
“The hardest goodbye is the one shared with someone you've spent the most time. The unbearable pain of losing someone woven into the tapestry of who you are is a lingering agony that reminds you with each breath a part of you is missing.