Mail is deleting my trash after 7 days but preferences say Never delete trash

I finally found a solution! On my computer settings I went to iCloud and unchecked iCloud Drive. I don't know why that works but I read some other posts that talked about iCloud drive causing various problems so I tried it. I don't use that feature so I don't lose anything by turning it off.

Thanks, BobTheFisherman, I checked the email provider's webpage and did not find anything about deleting. I also called my host twice and neither tech i spoke with could find any setting that would be causing it. My husband's email account on his laptop is behaving the same way--deleting mail from trash after 7 days--though he has his preferences set to delete trash after 1 month.

I think I have found the correct setting. On my phone I followed this path:

Settings, Apple ID, iCloud, Mail (there are two options for Mail; this is the one all the way at the bottom of the list), Advanced. Then I selected "Never" for Deleted Messages/Remove. I will update in a couple of days to confirm that this solved the problem.

My phone did not have "Never" Selected, but it had "1 week."

Changing the setting as described above DID NOT work. Mac is still deleting my trashed emails after 1 week. I don't know what to do. Does anyone have any ideas?