Adjunto un archivo al correo electrónico para enviárselo a mi profesora.

Here it’s the verb adjuntar in the 1st person singular present: “I attach.” Verbs don’t change for gender, so both men and women say Adjunto un archivo.

If you use adjunto/adjunta as an adjective, it agrees with the thing attached:

• Va adjunto el archivo.
• Va adjunta la factura. But that’s a different structure from the one in your sentence.

You can omit it. Adjunto un archivo is often enough because it’s understood you attach files to an email. If you include it, the most idiomatic options are:

• Adjunto un archivo a este correo.
• Adjunto un archivo al correo. “Correo electrónico” is fine, just a bit more formal or explicit.

With adjuntar, the standard is adjuntar algo a algo:

• Adjunto un archivo al correo. You can use en in a different structure:
• En este correo adjunto un archivo. But after the verb adjuntar, use a.

Spanish changes le/les to se when they come before a direct object pronoun (lo/la/los/las) to avoid the sequence “le lo.” So:

• “enviarle + lo” → enviárselo Here, se = “to her” (your teacher), and lo = “it” (the file).

Lo stands for un archivo (masculine singular). Change it to match the thing you’re sending:

• la (fem. sg.): una foto → enviársela
• los (masc. pl.): unos archivos → enviárselos
• las (fem. pl.): unas fotos → enviárselas

Yes. Both are correct:

• para enviarlo a mi profesora (no clitic doubling)
• para enviárselo a mi profesora (with clitic doubling) Spanish often doubles the indirect object with a pronoun (here se) when the recipient is expressed with an “a + person” phrase, but it’s not strictly required. Using se helps clarity and is very common.

With an infinitive like enviar, the pronouns attach to the end: enviárselo. If you rephrase with a conjugated verb, you have options:

• Se lo voy a enviar.
• Voy a enviárselo. But inside the para + infinitive purpose phrase, they must attach to the infinitive: para enviárselo.

Grammatically yes, but it sounds odd because you don’t attach a file “to a person”; you attach it to an email and send it to a person. Prefer:

• Adjunto un archivo al correo y se lo envío a mi profesora.
• Or simply your original: the purpose clause already ties the actions together.

Yes. Mandar is a very common synonym of enviar in Spain:

• …para mandárselo a mi profesora. Register-wise they’re both neutral in this context.

You’ll hear all of these in Spain:

• el correo / el correo electrónico (neutral; “electrónico” is more formal/explicit)
• el email / el mail (very common in speech and informal writing)

In your sentence (verb), no: always Adjunto un archivo. You use adjunta only when it’s an adjective agreeing with a feminine noun:

• Adjunta encontrarás la factura. (adjunct adjective with implied “factura”)
• Va adjunta la factura.

Yes:

• Adjunto un archivo al correo.
• Adjunto al correo un archivo. Both are fine. Spanish word order is flexible as long as the prepositions and pronouns are correct.