FormalName
Dear Mr/Mrs/Ms/Mx White,
Dear Sir/Madam,
Previous contact
Thank you for your email of.....
With reference to your email sent [date],.....
Reason for writing
I'm writing to let you know that .....
Yours faithfully,
Yours sincerely,
More informalName:
Hi Ben, Dear Ben,
Ben,
Previous contact
Thanks for your email.
Re your last email, ...
Reason for writing
Just a short note to let you know that....
Best wishes,
All the best,