People sometimes ask me about closing a business email: how do you sign off?
The main consideration is the relationship you have with the person to whom you are writing. If you are on a first-name basis, then think about what you’d say in person. You might be very casual. Some of these might fit your style:
Have a good one
If you are writing to someone you don’t know well or who is in a position above yours, you should tend toward more traditional closings:
Sincerely—I favor this one because no matter what you have written, I hope you have been sincere.
Yours truly—This one annoys me because how many people we write to are truly ours?
In addition to commonly used closings, you can also close using thoughts that are pertinent to what you have just written:
Keep up the good work
Thanks for your time
I look forward to hearing from you
When you use a two (or more)-word closing, only the first word is capitalized. If you are writing to a group and you know some people more casually and others less so (some of the people you may never have met), address your closing to the latter group. Avoid slang.
In all instances, your closing needs to fit the tone of the content. If you have been critical, stern, annoyed, or even angry, then you certainly don’t want to close with “Warmly” (even though you may be hot under the collar).