My Mac is connected to the internet, but my Mail says it is offline, so I am not receiving incoming mail and I cannot send mail.

This message would typically indicate an issue with either the email provider's server, an Apple Mail configuration error, or a email credential error.

Have you tried using the Connection Doctor? If so, what were the results?

Ref: Use Connection Doctor in Mail on Mac - Apple Support

In Mail Tool Bar At Top Menu " Mail "and Take all account Off line pause and Take All Account On Line

Is it resolved - the malware? If not, good application called Malwarebytes - free or paid for added features should clear this up

I also have the same exact issue and there seems to be no article on this site to fix it. It won't go online when I try. My google account in the app is online. I can receive emails to my iCloud account but I cannot send them.

I tried the malware bytes and now I can’t even log onto half the websites I had open and my google account is now offline. It also cannot connect to the App Store either. This all seemed to happen after an iOS update. I now really need help.

Yes, I have used the Connection Doctor and the green dot shows saying its online.

I can not read my emails - not connecting although I am on line

Welcome and Thank you too ;-)