account creation welcome email contains no to: address

I have upgraded to the latest version, upgraded my php version, everything is working fine with the exception that when a person creates an new account the welcome email bounces back with this expanation "A message that you sent contained no recipient addresses, and therefore no
delivery could be attempted." Subsequent emails to the new account are sent out just fine, but the welcome email gets no to: address defined.

where do I fix this?

do you have "Send Copy of Create Account Emails To" turned on in the admin>configuration>E-Mail Options? If you do then you most likely have the emails to send those additonal copies too formated incorrectly (Name 1 email@address1, Name 2 email@address2) or you have a hanging comma at the end of that list....I have seen that happen when removing an email off the list and the comma gets left...the system assumes there is suppose to be another email but then finds it as blank

thanks, fixed, the hanging comma was the problem, appreciate your help and experience