It looks like there could be a fallout still from the Google outage as email addresses are being flagged by the system as non-existent this would appear to be the Google end or something in between.
If you're having problems please can you post below and say whether it's a gmail address or not (but don't disclose your full email).
ta
Scott
If you're having problems please can you post below and say whether it's a gmail address or not (but don't disclose your full email).
ta
Scott