Oftentimes my friends and I discuss what the proper usage is for greetings and signing off professional e-mails. I work with a lot of internal colleagues and clients alike from all sorts of different fields, and it’s been tough to come to a conclusion as to what’s proper or not, but I think this will serve as a pretty good guide, just in case you’re planning on doing business in Brazil!
For Formal Business/Government Letters:
Greetings -
Prezado Senhor/a (nome):
Estimado Senhor/a (nome):
If you don’t know the person’s name, “Prezado Senhor/a,” or ”Estimado/a,” both work.
Also, if it’s more than one person, adding simply “Srs” or “Senhores” to the end of the greeting can work as well.
Ex. “Prezados Senhores:”
After greeting them, you might want to follow with what it is you are getting at with the letter.
A good introduction is:
Venho através desta para… – Literally, “I come through this for…” But what it means is ”I am writing this letter to…”
Sign-offs -
Atenciosamente,
Grato,
Cordialmente,
A “thank you” before signing off is always nice too…
Ex. Agradeço-lhe a atenção.
Formal e-mails usually follow the same lines, only things tend to be abbreviated.
Formal E-Mails
Greetings -
Caro,
Prezado Sr/a.,
Sign-offs -
Atenciosamente (or Att.),
Grato/a,
Informal E-mails/Letters
I’m personally a big fan of hugs and kisses and smiley faces all around, but I have to be careful as to not send hugs to a client on a first contact. I will usually use one of the greetings above, or simply the person’s name for an informal e-mail. Another greeting can be a simple “Oi (nome)!” (ok, I may have added the exclamation point as something only I do…)
Sign-offs
If it’s an informal e-mail to a client or coworker, Att works just fine.
If you’re more friendly with your client or coworker, or if it’s a good friend, Abraços, is a good sign-off. Especially in Brazil where hugs are welcomed 
Since I’m even more Brazilian, I will often end e-mails with Beijos, the same way I would end an informal e-mail to a friend in the US with “Love,”. Just be careful if you’re sending this to a coworker of the opposite sex. They might not take it as friendly as you mean for it to be!
Happy Writing!
beijos,
- poly
