SMTP stopped working Friday

SMTP email working fine from Globiflow for years then Friday nothing working right.

Globiflow smtp outgoing email appears to have stopped on Friday 2 July at about 17:52 BST

Globiflow mail handle trying to send mail instead but all being trapped at the receiving end spam filters.

Get a red error authentication box in Globiflow account saying cannot authenticate some php warning. I can send and received from that cpanel mailbox to outlook?

Asking to reconnect smtp account so re-entered details. Now wont even set it up.

What has changed?