I just found over 500 notification emails in my Email Error Log, all from the past 2 days when Invision migrated my community to the Cloud. All of them read: 

Error:  php_network_getaddresses: getaddrinfo failed: Name or service not known

I checked my email settings and noticed that the Mail Delivery Method was still on SMTP with the old settings from my self-host SMTP info. I switched it to: Invision Community in the Cloud : Uses Invision Community servers to send emails. - It sent me a test email which I received as expected.

Then I went to the Email Error Log and started clicking the "Resend Email" button on a few of the emails, including one that was addressed to me. The emails appear to be sent successfully, however I never received the one that was addressed to me? I tried to resend another one that was addressed to me, never received it either. No emails in my spam box either. 

I am however receiving new notifications since I've changed the Mail Delivery Method to Cloud. Just not the ones I resend from the Email Error Log. 

If you are resending items which have another method, those would not resend. The issue is you were previously using your own mailing method of PHP mail on your own server by the look of it. SO yes, switching to cloud email would resolve that going forward.

Ok thanks Marc. 

Wait, is there a way for me to use my Google email SMTP settings to resend these emails? 

In other words, now that I'm in the Cloud, can I still use any of the 3 provided Mail Delivery Methods?

Yes, you can switch to SMTP and set up google mail if needed

Great, thanks!