My wife upgraded my computer yesterday to High Sierra. I am unable to receive emails now on the basic email package. I can send.

Any suggestions for a fix? I called Frontier and they say it is not their problem. Also, My computer is running very slow.

Try this-

Fix Problematic Mail Account Settings After OS X Updates

-Open Mail app in OS X, then pull down the “Mail” menu and go to “Preferences”
-Now go to the “Accounts” tab, and select the email account which the problem is occurring for, then click on the “Advanced” tab
-Look for the box titled “Automatically detect and maintain account settings”, then do as follows depending on what situation you find:
-If it is unchecked, check it – then relaunch Mail app
-If it is checked, uncheck it, then quit and relaunch Mail app, then go back to the same preference setting and check the box again, then relaunch Mail app yet again
-Repeat this process for other email accounts in Mail app if necessary

Thanks, I ended up calling Apple and they had me go into the preferences and re-enter the passwords and it fixed it.

Good deal!

One issue I had involved multiple accounts; turns out I had to edit Outgoing Mail Server (SMTP) list. Each gmail account, for instance, wanted its own SMTP address if I wanted a reply email to have an unchanged email address (the program was changing my email address). Clear as mud, huh?

My ace is knowing the folks will talk all day for free about any mac issue, even looking at my devices.