Mail not verified

I use the plugin Publish Press and I really enjoy it but there is a small issue that i could figure out how to solve.
When the mails are sent to the subscribers here is always a warning message saying that google could not verify if the mail was really coming from the mail I putted for this service.
There is a way in the plugin to solve this problem maybe logging in using the google credentials? If you can help me to solve this problem i would really be pleased, thanks.