mail accounts offline
My mail accounts in macbook pro are constantly going offline. I thought that upgrading to El Capitan would help, but did not. Thanks..
MacBook Pro 15″, macOS 10.15
Refer to If you can’t send or receive email on your Mac - Apple Support.
If that does not help, the easiest way to fix it might be to delete the account from System Preferences > Internet Accounts. Then, add it again using that same Preference pane. Those instructions are provided in Set up Mail with email accounts - Apple Support.
Needless to say, if you are using, or have used at any time in the past, any non-Apple "anti-virus", "cleaning", or "Internet security" products including "banking security", anything at all in that broad category of utterly useless garbage, don't. A lot of things won't work if you do.