high water mark notification

Not sure if you figured out your problem ... I had the same problem with Roadrunner/Spectrum.

By default, you only get 10 MB of storage for email items. If you log onto the Spectrum webmail page (Log In), you'll see that you have folders such as "Junk" and "Junk Email". In my case, the messages in these two folders were taking up almost 10 MB. (Click on Manage Folders to see how much disk space each folder is using ... you can also delete folders here, if you want.)

You can do two things:

1) Go to Settings, Manage Mailbox Accounts, click on the email address of your account, and increase your Allocate Quota. In my case, I was able to increase it from 10MB to 28GB!

2) Go to Settings, Junk Mail Options, and verify that the filtering action is set to something other than "Place the email in the Junkmail folder". I switched mine to have junk mail delivered ... I already have junk mail filtering on my mail client.

I have never received this notification until the last few months. My email provider is Roadrunner which is now under Spectrum and my operating system is Windows 10. Those are the only two changes. Is it possible this notification has something to do with one or both of these changes? Any suggestions on how to fix this? I don't have a lot of emails on my server at this point and in the past, I've had many, many more but never received this notification.

Something you've installed that monitors flood stages?

Ssounds like you are approaching your storage quota on your email server

either delete some email, or move it into local storage mailboxes. To create one, click on the Add button at the bottom of the mailbox list. Choose New Mailbox, and set the location under On My Mac. Then, drag your old, unnecessary emails into that folder. You can create many folders to organize as you move them off the server.

Contact the e-mail provider for more information.

You are welcome.

You need to contact your e-mail provider to find out what the e-mail means.