I recently started having this issue and I'm not sure why. I have not made any changes to anything. I have Outlook 2007 on my laptop. I set up Outlook on my Galaxy S10E to have my emails handy on my phone. This is a work email and only work emails are received.
This is what is happening. I receive an email from Janedoe@email.com 9:30am Subject JohnDoe - Preview of the email says: Hello I'm reviewing customer file...
I open it, I read it, I may respond, or I may respond later on my laptop.
The next day, Janedoe@email.com sends another email 10:30am Subject JohnDoe - Preview of email - Hi I received the documents...
When I open that email, the body of the email is what I received yesterday. The date says "yesterday" but it's the exact email she sent me the day before.
The email preview "Hi I received the documents" is nowhere to be found.
I can't say i understand what is going on, but I would start by accessing the webmail version of the account and try to get clues there.
Also if the error is happening consistently, then it would be easier to troubleshoot.
Try to link the error to one device or the other. I would take the phone out of the equation by turning it off or disabling the account, then have someone send some test emails just to the computer. Then do the same just to the phone, with the computer off.
Thank you @Vincenzo. Everything is fine when I open it on the laptop. I uninstalled the Outlook app on my phone and reinstalled it. It seems it started happening after an update on my Samsung. I will give it time and check emails on my phone to see if the uninstall worked.