Mail not syncing between devices

[auntyj]

I have an iPad Pro, an iPad mini and an iPhone SE, all running IOS 10.3.2. The Pro and the iphone were purchased within the last 12 months. The Pro is my main device.
I constantly have a problem with the mail app. Whenever I check the mail on the iPhone or the mini, I find messages in the inbox that I've already deleted on the Pro, even when all devices are currently at home on the same wifi. The app won't allow me to delete these messages again, and gives me the error message that, "The message could not be moved to the trash."
If I open and delete a new message on the iPhone or the mini, I then have the same problem on the Pro.
The only way to fix it is to turn off the mail in settings and then restart the device.
All my settings are identical to what they were when I had an iPad 2 and an iPhone 4S. I was using the 4S with IOS 10, but I can't remember if I had the issue with that phone, or if it started with the new phone.
The iPhone also randomly asks me to re-enter my password for Hotmail in the settings as well, quite often.
Any suggestions please?
I'm assuming it's probably a software issue, but I'll post in the iPad Pro forum as well.

 

[scifan57]

I’ve deleted the thread you started in the iPad Pro forum as we only allow one thread per topic. Having multiple threads on the same issue, can confuse things and make it hard to follow the conversation.

 

[J. A.]

The problems you’be described happened to me as well. I think this is a problem with Hotmail and it’s settings, not with the software on your devices or the devices themselves.

If possible, login to Hotmail via browser, and take a look at it’s settings. Make sure you allow apps and devices to delete emails.