ERROR: 454: 4.7.0 Temporary authentication failure: generic failure

[servergcp1]

SYSTEM INFORMATION
OS type and version	Ubuntu Linux 20.04.6
Virtualmin version	7.5

Getting this error while configuring SMTP in my gmail.
Need fix please

[servergcp1]

Also, shows certificate subject and hostname mismatch, need that fixing too

[servergcp1]

The remote certificate is invalid according to the validation procedure: RemoteCertificateNameMismatch

[tpnsolutions]

@servergcp1,

Looks like the domain used for SMTP host does not have a valid certificate setup.