Search on server does not retrieve all the emails containing the keyword

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App version

6.400

Where did you get the app from?

F-Droid

Android version

LineageOS 19.1 / Android 12

Device model

Samsung Galaxy S7

Steps to reproduce

Use a Outlook.com account in K9.

• Go to your sent folder
• Search for a first name "one" that is contained in the email address like one.two@example.com
• Click on the "distant search icon" to make a request on the server

Expected behavior

Like in the Outlook.com web interface :

• all emails in the folder containing "one" in the email address are found and retrieved
• all emails in the folder containing the word "one" in the body are found and retrieved (in the body it can be a mention of the person or a signature)

Actual behavior

• K9 retrieve only 2 emails (I think the first email is already local in k9 and match the email ; and the second email retrieved is because it is the only one with one in the subject)

• The Outlook web interface retrieve more than 50 emails

• It looks like when you do a remote server search from K9 for a full email like one.two@example.com it does not works either.

Logs

No response

Start with the remote/server search flow invoked by the distant search icon while viewing the sent folder. Reproduce the Outlook.com case on the listed app and Android versions, then trace how searches for an email address and body keyword are handled; done means matching messages are retrieved consistently with the stated expected behavior.