Før jeg sender emailen, gemmer jeg et udkast og læser hver rettelse én gang til.

This is because Danish follows the V2 rule in main clauses: the finite verb usually comes in the second position.

Here, Før jeg sender emailen is placed first as a whole unit. That means the main clause has to begin with the verb:

• Før jeg sender emailen, gemmer jeg et udkast ...

If you remove the first clause, the normal word order is:

• Jeg gemmer et udkast ...

So the inversion happens because something else comes first.

Danish often uses the present tense for actions in the future, especially after time words like før, når, and efter.

So:

• Før jeg sender emailen
  literally looks like Before I send/am sending the email,
  but naturally means Before I send the email.

This is very normal in Danish.

Because emailen is the definite form, meaning the email.

In Danish, definiteness is usually shown by adding an ending to the noun:

• en email = an email
• emailen = the email

So instead of using a separate word like English the, Danish often adds -en or -et to the noun.

You may also see other spellings in real life, such as e-mailen or sometimes mailen.

Because udkast is a neuter noun in Danish.

Danish nouns have two genders:

• en-words
• et-words

Since udkast is an et-word, it takes:

• et udkast = a draft
• udkastet = the draft

Unfortunately, noun gender usually has to be learned with each word.

The verb gemme can mean several related things, such as:

• save
• store
• keep
• sometimes hide

In this sentence, because it is about an email and a draft, gemmer means save.

So gemmer jeg et udkast means I save a draft.

Because hver means each or every, and in Danish it is followed by a singular noun.

So:

• hver rettelse = each correction
• hver dag = every day
• hver elev = each student

Even though the meaning can refer to multiple things overall, the noun after hver stays singular.

Én gang til means one more time or once again.

The accent in én helps show that it is the number one and gives it emphasis. That makes it different from en, which can also be an article meaning a.

So:

• én gang til = one more time
• en gang can sometimes just be the ordinary phrase a time / one time, depending on context

In many everyday texts, people may leave out the accent if the meaning is already clear, but using én is helpful when you want to stress one.

Because the same subject, jeg, applies to both verbs:

• gemmer jeg et udkast
• og læser hver rettelse én gang til

In Danish, when two verbs share the same subject, it is very common to mention the subject only once.

So this means:

• I save a draft and read each correction one more time

You could also say:

• ... og jeg læser hver rettelse én gang til

but that sounds a bit more explicit or emphatic.

Because Før jeg sender emailen is a subordinate clause placed before the main clause.

The comma separates:

• the introductory clause: Før jeg sender emailen
• the main clause: gemmer jeg et udkast og læser hver rettelse én gang til

This kind of comma is very common in Danish writing.

Rettelse means correction, edit, or change made to fix something.

Depending on context, it could refer to:

• corrections in the text
• edits suggested by someone else
• changes the writer wants to review

In this sentence, hver rettelse suggests the person is carefully going through each correction in the email before sending it.