Ohne Empfänger kann die E-Mail nicht abgeschickt werden.

Ohne always takes the accusative case in German. So the noun after it must be accusative.

Here, Empfänger is a masculine noun, and in the singular accusative it would normally be:

• ohne den Empfänger = without the recipient

But German often leaves out the article when speaking in a general, non-specific way, especially in technical or interface-style language. So:

• ohne Empfänger = without recipient / without a recipient

As for Empfängerin, that is specifically female recipient. Empfänger can be used generically when no gender is being specified.

Because the sentence is talking about a recipient in a general sense, not a specific person.

Compare:

• ohne Empfänger = without a recipient / with no recipient entered
• ohne den Empfänger = without the recipient
• ohne einen Empfänger = without a recipient

In software messages and instructions, German often drops the article for a short, neutral style. So ohne Empfänger sounds very natural in a system message.

The singular here is being used in a generic way. It means that no recipient has been specified at all.

So ohne Empfänger does not mean there must only be one recipient. It means the email has no recipient entered.

German often uses the singular like this when referring to a category in general.

Because E-Mail is a feminine noun in German.

Its article is:

• die E-Mail = nominative singular
• der E-Mail = dative singular
• die E-Mail = accusative singular

In this sentence, die E-Mail is the subject, so it is in the nominative case.

Both are possible, but they emphasize slightly different things.

German main clauses follow the verb-second rule: the finite verb must come in the second position.

In this sentence:

• Ohne Empfänger = first element
• kann = second-position finite verb
• die E-Mail = subject

So the sentence is perfectly normal.

If you said:

• Die E-Mail kann ohne Empfänger nicht abgeschickt werden

that would also be correct. It just starts with the subject instead of the prepositional phrase.

Starting with Ohne Empfänger puts stronger focus on the condition: without a recipient.

Because in German main clauses, the finite verb must be in second position, even if the subject is not first.

Here the first position is taken by Ohne Empfänger, so the verb kann has to come next:

• Ohne Empfänger | kann | die E-Mail ...

This is a very common pattern in German.

This is a combination of a passive construction and a modal verb.

The basic passive sentence would be:

• Die E-Mail wird abgeschickt.
  = The email is being sent / gets sent.

With a modal verb:

• Die E-Mail kann abgeschickt werden.
  = The email can be sent.

So:

• abgeschickt = past participle of abschicken
• werden = passive auxiliary in infinitive form
• kann = modal verb

When a modal verb is present, the passive part goes to the end as:

• Participle + werden

That is why you get:

• kann ... abgeschickt werden

The full verb is abschicken, which means to send off / to send.

It is a separable-prefix verb:

• infinitive: abschicken
• present: ich schicke die E-Mail ab
• past participle: abgeschickt

So the ab- belongs to the verb itself. In the participle, the prefix stays attached:

• abgeschickt

Using just geschickt would come from schicken, which also means to send, but abschicken is especially common for actually sending something out, such as a letter or email.

Because German sends the non-finite verbs to the end of the clause.

Here you have:

• kann = finite modal verb
• abgeschickt werden = verbal cluster at the end

In clauses with modal verbs, the infinitive forms stay at the end. Since this is passive, the infinitive werden is needed there too.

So the structure is:

• Ohne Empfänger
• kann
• die E-Mail nicht
• abgeschickt werden

This is normal German word order.

Because nicht usually comes before the part of the sentence it negates.

Here, the idea being negated is the action being sent:

• nicht abgeschickt werden = not be able to be sent

So the sentence means that the email cannot be sent.

If nicht were placed somewhere else, the emphasis could change. In this sentence, its position is the standard one for negating the verbal idea at the end.

Yes, it is a passive sentence.

Passive:

• Ohne Empfänger kann die E-Mail nicht abgeschickt werden.
  = Without a recipient, the email cannot be sent.

An active version would need a subject that does the action, for example:

• Ohne Empfänger kann man die E-Mail nicht abschicken.
  = Without a recipient, one cannot send the email.
• Ohne Empfänger können Sie die E-Mail nicht abschicken.
  = Without a recipient, you cannot send the email.

The passive is very common in instructions, warnings, and system messages because it focuses on the action or result, not on who does it.

Yes, that is grammatically correct.

• ohne Empfänger = more general, compact, system-message style
• ohne einen Empfänger = a little fuller, more explicit

In everyday or technical German, especially in software messages, ohne Empfänger is often preferred because it sounds shorter and more natural in that context.

Because in German, all nouns are capitalized.

So in this sentence:

• Empfänger is a noun
• E-Mail is a noun

That is why they begin with capital letters. This is one of the most noticeable spelling features of German.