بعد ما فتحت الرسالة، اتصلت باختي.

In Egyptian Arabic, بعد ما means after when it is followed by a verb or a whole clause.

So:

• بعد = after
• ما = a linker that helps introduce the following action

In بعد ما فتحت الرسالة it means after I opened the message.

This ما does not mean not here. It is just part of the common Egyptian pattern بعد ما + verb.

Because in Egyptian Arabic, بعد ما is a very common way to say after doing something / after something happened.

Compare:

• بعد ما فتحت الرسالة = after I opened the message
• بعد الرسالة = after the message

So بعد by itself is often followed by a noun, while بعد ما is a natural way to introduce a full action or clause.

Because Arabic verbs usually already show the subject.

Both فتحت and اتصلت include the idea of I in the verb form, so you do not need أنا.

So:

• فتحت = I opened
• اتصلت = I called / I contacted

You could add أنا for emphasis, but it is not necessary:

• بعد ما أنا فتحت الرسالة، أنا اتصلت باختي would sound overly heavy unless you are stressing I specifically.

No. The ending is not because الرسالة is feminine.

The -ت here is part of the past tense verb form. It shows the subject, not the object.

That means فتحت is connected to the hidden subject I, not to الرسالة.

This is important:

• I opened the message → فتحت الرسالة
• The message is the object
• Arabic verbs do not change to match the object in this kind of sentence

Also, because Arabic is usually written without short vowels, فتحت can look ambiguous on the page. Context tells you it means I opened here.

It can mean either, depending on context.

الرسالة literally means the message or the letter.

In modern everyday usage, it could refer to:

• a text message
• a written message
• an email
• a letter

So the exact English translation depends on the situation, even though the Arabic word stays the same.

Because the verb اتصل normally takes the preposition بـ before the person you contact.

So the structure is:

• اتصلت بــ... = I contacted / called ...

That is why you get:

• اتصلت باختي = I called my sister

This is similar to how some English verbs need an extra word, like speak to someone or get in touch with someone.

اختي means my sister.

It is made of:

• أخت / اخت = sister
• -ي = my

So:

• أختي / اختي = my sister

That final -ي is a very common possessive ending in Arabic.

For example:

• أخي = my brother
• كتابي = my book
• بيتي = my house

This is a very common question.

In more formal spelling, especially closer to Modern Standard Arabic, you would usually write:

• بأختي

But in informal Egyptian writing, people often simplify spelling and leave out the hamza, so you may see:

• باختي

So:

• بأختي = more formal / more standard spelling
• باختي = very common informal Egyptian spelling

They mean the same thing.

It is natural Egyptian Arabic, especially because of بعد ما and the informal spelling باختي.

A more Modern Standard Arabic version would usually be something like:

• بعد أن فتحت الرسالة، اتصلت بأختي
• or بعدما فتحت الرسالة، اتصلت بأختي

So the sentence you were given is best understood as Egyptian colloquial, not formal written Arabic.

Yes. You could also say:

• اتصلت باختي بعد ما فتحت الرسالة

That means the same thing: I called my sister after I opened the message.

The version with بعد ما فتحت الرسالة at the beginning puts the time/background first, which is very natural in storytelling.

So both are fine:

• بعد ما فتحت الرسالة، اتصلت باختي
• اتصلت باختي بعد ما فتحت الرسالة

Not necessarily.

بعد ما tells you the order:

1. opening the message
2. calling the sister

But it does not by itself say whether the call happened:

• immediately after
• a few minutes later
• much later

If you wanted to emphasize immediacy, you would need extra words or context.

So this sentence mainly gives sequence, not exact timing.