Min veninde siger, at indbakken er fuld igen, fordi hun har fået for mange beskeder.

In Danish:

• ven = friend, traditionally male friend
• veninde = female friend

In modern usage, ven can sometimes be used more generally, but veninde clearly tells you the friend is a woman.

So:

• Min ven siger ... = My friend says ...
• Min veninde siger ... = My female friend says ...

Also notice:

• min is used with both ven and veninde
• Danish does not change min based on the natural gender of the person

Because siger is the present tense form of the verb at sige = to say.

So:

• at sige = to say
• siger = say / says
• sagde = said
• har sagt = have/has said

In this sentence, the action is happening in the present, so Danish uses siger:

• Min veninde siger ... = My friend says ...

Unlike English, Danish verbs do not change for different persons:

• jeg siger = I say
• du siger = you say
• hun siger = she says

It is always siger in the present tense.

Here at means that.

It introduces a subordinate clause:

• Min veninde siger = My friend says
• at indbakken er fuld igen = that the inbox is full again

So the full structure is:

• main clause: Min veninde siger
• subordinate clause: at indbakken er fuld igen

This is very common in Danish after verbs like:

• sige = say
• tro = think
• vide = know
• håbe = hope

Example:

• Jeg tror, at han kommer. = I think that he is coming.

In everyday English, that is often omitted, but in Danish at is very commonly kept.

Because indbakken is the definite form: the inbox.

Danish usually makes nouns definite by adding an ending to the noun.

For indbakke:

• en indbakke = an inbox
• indbakken = the inbox

This is one of the biggest differences from English. Instead of putting a separate word like the before the noun, Danish often adds the definite ending directly:

• en bog = a book
• bogen = the book

So:

• indbakken er fuld = the inbox is full

Because this is a subordinate clause, and Danish word order changes in subordinate clauses.

In a normal main clause, Danish often follows the verb-second rule:

• Indbakken er fuld.

But after at, the clause is subordinate, and the usual order is:

• subject + verb + complement
• indbakken + er + fuld

So:

• at indbakken er fuld = that the inbox is full

This is normal subordinate-clause word order in Danish.

Yes. fuld here means full.

So:

• indbakken er fuld = the inbox is full

A useful detail: fuld can also mean drunk, depending on context.

Examples:

• Glasset er fuldt. = The glass is full.
• Han er fuld. = He is drunk.

In your sentence, because it is about indbakken (the inbox), the meaning is clearly full, not drunk.

Also note that adjective forms can change:

• en fuld indbakke
• indbakken er fuld

The predicate form after er is fuld.

igen means again.

So:

• indbakken er fuld igen = the inbox is full again

In Danish, igen often comes late in the clause, especially after an adjective or past participle:

• Han er syg igen. = He is sick again.
• Døren er åben igen. = The door is open again.

So the placement in your sentence is very natural.

fordi means because.

It introduces the reason:

• Min veninde siger, at indbakken er fuld igen = My friend says that the inbox is full again
• fordi hun har fået for mange beskeder = because she has received too many messages

So fordi connects the result and the reason.

This is another subordinate clause, just like the clause after at.

har fået is the present perfect tense.

It is made with:

• har = has/have
• fået = past participle of få

So:

• hun har fået = she has received / she has gotten

In this sentence:

• hun har fået for mange beskeder = she has received too many messages

This tense is used because the messages were received before now, and the result is relevant now: the inbox is full.

Related forms:

• at få = to get / receive
• får = get / gets
• fik = got / received
• har fået = has/have gotten, has/have received

Because beskeder is a countable plural noun: messages.

In Danish:

• mange = many, used with countable nouns
• meget = much, used with uncountable nouns or in some other uses

So:

• for mange beskeder = too many messages
• for meget vand = too much water

Since you can count messages, Danish uses mange.

Also:

• for here means too, not for
• so for mange = too many

The singular is:

• en besked = a message
• beskeden = the message
• beskeder = messages
• beskederne = the messages

In your sentence, beskeder is plural indefinite, meaning just messages in general, not the messages.

So:

• hun har fået for mange beskeder = she has received too many messages

There is no article because English also usually says too many messages, not too many the messages.

Those commas mark the beginning of subordinate clauses.

Here the subordinate clauses are:

• at indbakken er fuld igen
• fordi hun har fået for mange beskeder

So the commas help show the structure of the sentence.

You will often see Danish commas used this way in writing. Comma usage in Danish can be a little tricky because there are slightly different comma conventions, but for a learner, it is very useful to recognize that commas often appear before subordinate clauses introduced by words like:

• at = that
• fordi = because
• hvis = if
• som = who/which/that

Yes, there are a few natural alternatives, but the original sentence is completely normal.

For example:

• Min veninde siger, at indbakken er fuld igen, fordi hun har fået for mange beskeder.
• Min veninde siger, at hendes indbakke er fuld igen, fordi hun har fået for mange beskeder.

The second version adds hendes = her, which makes it extra clear that it is her inbox.

Without hendes, the original still sounds natural, especially when the context already makes it obvious whose inbox it is.

You could also say:

• Min venindes indbakke er fuld igen, fordi hun har fået for mange beskeder.
  = My female friend’s inbox is full again because she has received too many messages.

That version changes the structure, but the meaning is very similar.