I left out two sentences I need to write in an email.

1) I wrote to the two Irish school's principals you suggested (to me) but none of them replied to my email.
2) As I would really like to start a school exchange programme with an Irish school in your area, could you please keep searching for a school?

1. I wrote to the two Irish schools' principals as you suggested, but neither of them replied.

2. I would really like to start an exchange programme with an Irish school in your area, so could you please keep searching?

To add the missing sentences to your email, follow these steps:

1) Open your email application or website and go to the drafted email that needs the additional sentences.
2) Locate the section or paragraph in your email where the missing sentences should be inserted.
3) Place your cursor or click on the appropriate spot in the email to ensure the new sentences are added in the correct place.
4) Type or copy and paste the first missing sentence: "I wrote to the two Irish school's principals you suggested (to me) but none of them replied to my email."
5) Type or copy and paste the second missing sentence: "As I would really like to start a school exchange programme with an Irish school in your area, could you please keep searching for a school?"
6) After adding the missing sentences, proofread the email to ensure it flows and makes sense with the new additions.
7) Once you are satisfied with the changes made, you can either save the email as a draft or send it to the recipient.

By following these steps, you should be able to seamlessly integrate the two missing sentences into your email before sending it.