This is the most ubiquitous; it's totally safe. I recommend it highly and so do the experts.
A little stilted. Etiquette consultant Lett likes it.
My best to you
Lett also likes this one. I think it's old-fashioned.
All the best
This works too.
Seems too much like a greeting card but it's not bad.
I know people who like this but I find it fussy. Why do you need the extra "s"?
More formal than the ubiquitous "Best". I use this when I want a note of formality.
Fine, anodyne, helpfully brief. I use this.
I used to use this but stopped, because it's trying too hard to be abbreviated. Why not type three more letters? OK if you're sending it from your phone.
I like this for a personal email to someone you don't know very well, or a business email that is meant as a thank-you.
As good as Warm Regards, with a touch of added heat.
I use this often for personal emails, especially if I'm close to someone but not in regular touch.
This is a nice riff on the "warm" theme that can safely be used among colleagues.
这是一个关于 “warm” 主题很好的结尾，在同事之间使用很安全。
In the right instances, especially for personal emails, this works.
Lett says this is a no-no. "This is not a closing. It's a thank-you," she insists. I disagree. Forbes Leadership editor Fred Allen uses it regularly and I think it's an appropriate, warm thing to say. I use it too.
Thanks so much
I also like this and use it, especially when someone—a colleague, a source, someone with whom I have a business relationship—has put time and effort into a task or email.
This rubs me the wrong way because I used to have a boss who ended every email this way. She was usually asking me to perform a task and it made her sign-off seem more like a stern order, with a forced note of appreciation, than a genuine expression of gratitude. But in the right context, it can be fine.
More formal than "Thanks." I use this sometimes.
This doesn't have the same grating quality as "Thanks!" The added "you" softens it.
I use this a lot, when I genuinely appreciate the effort the recipient has undertaken.
Thanks for your consideration.
A tad stilted with a note of servility, this can work in the business context, though it's almost asking for a rejection. Steer clear of this when writing a note related to seeking employment.
I predict this will gain in popularity as our emails become more like texts.
Hope this helps
I like this in an email where you are trying to help the recipient.
I use this too. I think it's gracious and warm, and shows you are eager to meet with the recipient.
This works when you really are rushing. It expresses humility and regard for the recipient.
Also good when you don't have time to proofread.
Some people find this grating. Not appropriate for a business email.
Retro, this sign-off wears its politics on its sleeve. It doesn't bother me but others might recoil.