"Уважаемые сотрудники посольства" = Dear Sirs,

e.g. Dear Consulate team,

Hi Database Management Team, (в другой отдел в пределах организации)
...

Hi Global Knowledge, (в организцию Global Knowledge)
...

До сих пор никто не одернул и не поправил, хотя может это пресловутая толерантность плюс для Global Knowledge мы - клиенты, так что можно повыпендриваться. Наверное, если выступать в роли просильца, то Dear Sir or Madame кашу не испортит. В оправдание, высокий смысл формата Hi <Такая-то компания> в первой же строке показывает что мы хорошо знаем к кому обращаемся (косвенно: вот какие мы деловые и сфокусированные).

No. 'Hi' is now standard when phoning people within your organisation. It's also very common if you're an outsider phoning an organisation, although you can use 'Hello' instead if you want to be more formal.

Written/typed business letters are more formal.

With business letters to one person you should use 'Dear Mr Smith' (or 'Dear Mrs Smith') if you know their gender and surname. If you don't know the person's gender or surname, it's 'Dear Sir/Madam' (as written).

With business letters addressed to organisations where you don't know the name(s) or gender(s) of the person(s) you're writing to, it's 'Dear Sirs' -- but never 'Dear Madams'. Blatant sexism, but it's true.

English greetings on business letters are usually much shorter than their Russian equivalents and follow set patterns -- so you wouldn't normally say 'Dear embassy employees'; it's just 'Dear Sirs'. 'Уважаемые специалисты грантовой службы' -- ditto.

Emails are half-way between phone calls and letters in their formality -- so use 'Hi' or 'Hi Mr Smith' if you want to be quite friendly, or 'Dear ......' (as for letters above) if you want to be formal.

--------------------

There are some variations on the above, but these are the general rules.

Dear Guys and Gals,
Dear Fellas,
Dear Lads and Lasses,

ЗЫ. вопрос не читал...

ЗЫ. тоже осуждаю

тема дисера, на минуточку, - что-то про е-governments постсоветского пространства

дите копает глубоко. не зря бухали!

поеду на защиту (благо зван) и поглумлюсь!

люблю я пышных интеллектов увяданье
в пиздец и срам переобутые гласа [sic.]

Если просто в какую-нибудь службу поддержки, то обычно начинаю с "Dear Customer Care Team,"

нормас
так и должно быть
важен action

например, Dear search committee members и т.п.

Невежливость, с которой чаще всего сталкиваюсь я, -- отстуствие приветствия вообще.

http://www.businesswritingblog.com/business_writing/2009/11/theres-no-excuse-for-dear-sir-or-madam.html

That greeting instantly told me that the letter writers were strangers who did not care enough about their communication with me to find out my name or my gender.

https://www.skillsyouneed.com/write/letter-writing.html

Never start a letter ‘Dear Sir or Madam’. In this day and age, there is no excuse for not knowing the name of the person to whom you are writing. Google the company to which you are writing, and use the correct name.

http://www.businessinsider.fr/us/worst-ways-to-address-a-cover-letter-2015-12/

The 5 worst ways to address a cover letter:

Dear Sir or Madam:

The fact that your opening isn't customized at all is a big turn-off.

Hi Very Dear Mr,

I name Donald and have much excitable offer to you for consideration at your respectful time...

Dear Grainger. Then deleted ‘Dear’ and substituted ‘Hi’, then deleted that and just had ‘Grainger’, then reinstated ‘Dear’, then deleted it again. Unwarranted intimacy versus unfriendly brusqueness . . . a flurry of confused gestures before communication could begin. Letter-writing must have been so much easier in the olden days when everyone, even the bank manager or the tax department, was Dear.

'Dear Sir or Madam' is standard practice in business correspondence, at least in the UK, when an organisation doesn't know the surname or gender of the person it's writing to/emailing.

Perhaps in an ideal world, people would spend time trying to research the name of each person they were planning to contact so that they could then insert the greeting 'Dear Mr Jones' (or whatever) -- but that's not what happens in practice.

'Dear Sir or Madam' is very common and isn't considered impolite at all. It simply means that the writer doesn't (yet) know your surname/gender.