First! Welcome to the forums
Second, do you have Veeam ONE? That might help you in configuring suppressing specific alarms (so you don't get the email alerts) and fine-tuning.
If you don't, take a look at this page: https://helpcenter.veeam.com/docs/backu ... tml?ver=95
I assume suppress notifications until last retry is checked here (not sure as you say Wait until last retry).
Also check this page: https://helpcenter.veeam.com/docs/backu ... tml?ver=95
You will see that disk space notifications are not the same as job notifications so you can play a bit with making sure that warnings are not seen.
Hope it helps