The admin alert only shows up when trying to send notice that a setting has changed. Every other email possibility works with no issues. I can use the send email function in admin with no problems. All customer emails get sent etc. I have upgraded the php mail functions using phpmailer files from April of 2017. Php version is 5.6.36. There's virtually no changed core files - especially anything that would have to do with any mail function. This cart was installed quite a while and has not been used as a live site til now so I don't remember much about it but no one else has touched this besides me.

Email settings are all default for php. yes to emails sending from known domain and in this case using an actual email account on the same server.

Anyone got a guess to what's happening?