Welcome to TPG Community!
What type of email client are you using to set up your TPG email?
If you are using a client, have you tried to uninstall and reinstall it? Also, are you able to use a different email client to compare if you are going to experience the same thing?
You may also try to set up your TPG email on your phone if it's going to go through or not.
Please keep us posted if nothing is working and will look into it further.